Disclaimer: I don't claim to own either Final Fantasy or Harry Potter, they belong to their respective creators.

Harry Potter/ Final Fantasy X Crossover.

Dark Summoner

By: Mage-Alia

Chapter 17: I'm on my way…

Summary: An accidental wish on a certain mirror sends Harry tumbling into the world of Spira where his skills as a Summoner will be put to the ultimate test, but he won't be alone. Accompanied by Tidus, the misplaced hero, Auron, the moody monk with a past, Rikku, a happy go lucky new friend and Oa'ka, the merchant turned wizard, Harry will need to conquer the challenges that lay in his path as he seeks out the truth of Spira's Spiral of Death.

A/N: …..Unfortunately…. you won't get the Lemon… like I said, I kinda wrote it out of the story. If I ever get up the nerve to do so I'll revise the story and put something in but until then I'll let your imaginations fill in the gaps between the end of the last chapter and the start of this one. So just to start you off, see what you make of this.

Once again it was the light that woke them.

The clearing with the spring was wide enough that the sun could shine down into the forest unhindered by the trees. Tidus just rolled over and soaked in the rays without a care in the world, quickly returning to sleep. However, his sleep was broken again by something moving beside him.

"Tidus…" Harry moaned faintly as he pushed himself up off the dragon Animagus's chest. "…come on, get dressed. We can't be like this if Rikku decides she wants to come and find us, or even worse, Yuna."

That got him up.

They where both alert and ready to go when someone actually did come to find them. Lulu took in the sight of them both as she arrived and instantly arched an eyebrow in mild amusement.

"When you weren't in the camp I was volunteered to retrieve you." She said, a slight lilt to her voice. "I am glad I did not come sooner or I might have seen something I would not have liked to see." Harry went atomic red and put his head down as he began to giggle. Tidus just stood there grinning like a maniac and Lulu shook her head in exasperation.

"I was told to inform Summoner Harry that Yuna will be continuing her Pilgrimage. Since we are traveling to the same destination we wondered if you would consent to combining our forces until we reach Zanarkand?" Harry just shrugged flippantly, not in any kind of mood to be enduring formalities.

"I won't stop you if you do." He said simply as they began to walk back in the direction of the camp.

The other's where waiting when they arrived.

Rikku was half way up a tree with Gatta, swinging her legs while she chattered away, Auron was leaning on the base of the tree, his sword propped against his shoulder while Oa'ka was hassling Wakka. Yuna stood solemnly beside Kimahri and blushed when they looked in her direction.

"Well? Are we going or what?" Tidus asked and they gathered before setting out along the now wider forest road. Rikku and Gatta scampered ahead, scouting the way while Harry and Yuna where pushed to the center of the group, surrounded by Kimahri, Tidus and Auron. Lulu and Oa'ka took up the rear, talking in low voices about various black magic spells and how to improve on them. At least and hour had passed when the tree's began to thin out, allowing more and more of the early morning sun light to filter through the leaves. The forest ended right up against a moss covered rock wall and they where forced into a bottle neck ravine where the dirt of their path gave way to grass and opened out onto one o the most incredible views Harry had ever seen.

They stood on a wide ledge that over looked a vast grassland plain that went on for as far as the eye could see and then some. Harry just couldn't keep the smile off his face as a stray thought about the Sound of Music ran through his head.

'Need's more hills.' He decided looking over the low lying, grass covered mounds of earth to where an equally as low structure was built. He was shaken from his thoughts by a thump and turned to see that Yuna had fallen on her back, staring up at the sky unseeingly, lost in thought. While they stood, taking in the view Lulu broke the silence.

"Long ago the High Summoners fought Sin here." She said almost reverently, her eyes drifting toward the west where the plains just simply ended. "The road ends here. Beyond, there're no towns, no villages. Only endless plains." Auron sent her a rather disgruntled look that said something along the lines of 'I knew that'.

"Many Summoners stray from their path and loose their way here." He added to the description in his low deadpan voice. No one really said anything after that and Kimahri helped Yuna to her feet as she mumbled something to herself. Harry looked at Tidus behind their backs and raised a hand beside his face, making a swirling motion around his ear and crossing his eyes. He stopped a moment later when the blonde burst out laughing. Wakka, Lulu and Yuna gave them both odd looks but the other's, bar Kimahri, where used to the silent conversations that seemed to go on between the Guardian and Summoner.

Putting the incident aside they began to pick their way down the gentle slopes and moved onto the rolling plains, making for the distant dot on the horizon.

"HEY! STOP! COME BACK!" Oa'ka streaked across the grassy hills and took a flying leap toward his prey, sailing through the air for a moment before he crash-landed face first in the dirt.

Harry laughed.

Oa'ka looked up with a disgruntled expression on his face.

"It's not funny." He pouted before walking to where he'd dropped his staff. He'd taken one look at the endless grassy plains and instantly wondered off to chase the Chocobo's.

So naturally, he hadn't had much luck in catching them.

As the merchant turned black mage stomped around muttering Harry turned his attention to the big golden form that was twisting lazily around in the clear blue sky. Tidus, on the other hand, had an affinity for the birds. One would think that being a dragon would scare them away but this wasn't the case. They had flocked to him the moment he'd transformed, all clamoring for his attention. Which was mostly why Harry was sitting on one now. Riding a Chocobo was kind of like riding a Hippogriff; except there weren't the back legs of a horse to mess up the way it walked, assuring a much smother ride. They'd found a lady earlier who had been riding much as they where and she had told them that the Chocobo where very intelligent and loyal creatures. If they sensed you where good they would follow you regardless of size, shape or species, Tidus being a prime example.

After an hour the younger two members of their group had gotten bored and begun to goof off, riding circles around the rest of the group. The older members where enjoying the relative peace and quiet, Harry also knew that Auron was sleeping in the saddle. The older man was rocking with the motion of the Chocobo that carried him as it trotted somewhere in the middle of the group. The green-eyed Summoner hadn't been to sure at first so he cast a discrete scan spell and sure enough, the man was sleeping…

The man snapped awake a moment later though when there was a roar from the west and everyone looked toward the source. Tidus had found something. Harry leaned down over the neck of the Chocobo and urged it forward at a faster pace. It didn't take long to catch up and this time the sight that awaited them left Harry completely speechless.

It was as though the earth had dropped away leaving a great expanse of nothing. It was hundreds of miles down the cliff face that the ground leveled out, nothing grew there and most likely never would. Harry looked over at Tidus in askance but the Guardian could only give him the draconic equivalent of a shrug. Harry looked over to Auron instead.

"… The calm lands have long been a battle ground for those who confront Sin." He explained. "It wasn't always this calm. It was said there used to be great forests and mountains here but they where destroyed in the Summoners battles." He indicated another direction with a nod of his head.

"Over there is there is the Scar." Harry let his Chocobo trot along the cliffs until a great chasm became distantly visible. "It was created by one of the first Summoners in a battle with sin… or so they say." He fell silent and backed away heading for the Al Bhed outpost, which was now much closer than it had been before. The others followed him but Harry didn't feel like going and neither did Tidus. So Harry got off his Chocobo and turned it lose before walking over to where Tidus had changed back to human. A frown marred his expression as he took another look over at the canyon. Something was screaming at him, in his mind the image of the plains was over laid by another one, a scene he'd left behind him, back in the past,

"Harry?" The Summoner looked up to see Tidus looking slightly concerned. "What's wrong?" Sure he could look into Harry's thoughts but that didn't necessarily mean he always understood them.

"I… I think I know this place." He absentmindedly registered Tidus holding his hand as he walked in the direction of the canyon. He stared at the ground and even managed to walk a full circle around a large stone before heading off in the right direction. Eventually they came to a stop at the edge of the scar and stared down into its depths. Unlike the dead land to the west that stretched off into the distance they couldn't see the bottom. The narrow rift was shrouded in mixed residual energies that felt positively ancient. They walked along it in the direction of the mountains before Tidus noticed a path leading down the cliff. Looking at Harry he noticed that the Summoner was deep in thought. Leaving him at the top of the path Tidus ventured down a little way before he noticed a scent in the air. Someone had been there recently. Moving further he stopped has his foot hit something with the ringing chime of metal. Crouching down he brushed aside the dirt and found himself holding a sword. Rubbing away more of the caked dirt the blade was slowly revealed.

It was made of pure gold and silver with long strips of some blue gemstone embedded into the metals. From what he could tell the hilt was made of the same materials and wrapped in royal blue leather. Tidus couldn't take his eyes off it and was ready to clean off the rest of the dirt when both a mental and physical cry of distress shook him from his thoughts. Without really thinking and with the sword in hand he bolted up the path to find Harry on his knees. A quick look said he was unharmed but even so, he was staring at the Scar in pure horror.

"This is the place…" He murmured just loud enough for Tidus to catch. "…this is where it happened…" He looked ready to cry as his gaze drifted out to the wasteland once more.

"Hogwarts really is gone…"

Harry's mood was grave when and Tidus finally caught up with the others. It was late in the night and the moon was high in its arc across the nighttime skies. Normally Harry would have stopped to look at the unimpeded view offered by the Calm lands low lying plains but he just couldn't bring himself to look up.

The Scar…

That crevice had seemed so familiar because he'd seen it before. The battle with Voldemort had taken place miles away from Hogwarts on the outer edges of the Forbidden Forest, closer to the mountains than anything else, even though the battle sight had been visible from Hogwarts... come to think of it… what remained of the Scar now was only a small portion of what it had been. He hadn't even recognized the land around him for what it was. The ever-present hum of ambient magic that had come with the forest had disappeared over time along with the enchanted woods and its creatures. Harry's eyes drifted back to the west again, ignoring the fuss that was springing up around him. He'd seen maps of Spira, but none had held all that much resemblance to the Islands of the United Kingdom. What had happened to cause such a drastic change in the landscape that not even he could recognize his old home?

He came back to the present when someone sat down nearby. Looking across he noticed it was Maechen, the old scholar they'd met on the Thunder Plains.

"Ahhh!" He let out a soft kind of sigh as he settled down by the campfire that was burning merrily in the makeshift Inn of the Al Bhed out post. It was little more than a tent really. It was low to the ground and had no real luxuries. Most of them where quite used to roughing it by now, so they didn't really miss them.

"Its wonderful to see you again Master Summoner!" Maechen said in his wizened voice. Harry flinched at the name. Now that the Maester's knew he'd quickly resigned himself to hearing that particular title but so soon after seeing the Scar… Maechen went on, ignoring, or not noticing the reaction.

"You know I studied a little about the calm lands you know. I don't quite remember where but I could tell you about it, if you wish." Harry frowned as he thought.

"… A lot of the land here has changed, what caused so much land mass to just disappear?" Harry asked the question he'd been pondering for a while. Maechen gave a faint nostalgic smile.

"It has been many a year since you last walked here." He began waving a hand vaguely to indicate the surrounding areas. "Sin is a great destructive force, when he first appeared he destroyed many things. His attacks carved out the land to make it what it is today. When the forests of the calm lands died Summoners began using it as a battle ground to combat Sin. Their powers clashed violently and what you see to the west is part of the overall result. Spira has long since lost all contact with anyone remaining outside of our borders, leaving us as the souls responsible for Sin." He'd been rambling off tangent slightly before he finished speaking but Harry still understood the gist of what he was trying to say. In the end it all brewed down to the one thing that mattered. Both Sin 'AND' the Summoners had been responsible for the destruction of where Hogwarts had been…

But then he thought of something.

"Sir, if the lands where destroyed and my home Hogwarts along with it… then why can I still summon my Aeons?" Maechen stared at him pensively.

"That's a very good question." He responded, thinking deeply as he tried to recall what he knew. "Ah, yes, I remember now." Maechen sat up straighter.

"There where once records that explain that after the time of the Master Summoner, Summoning became popular once more. With the legendary school of magic closed to most of those who had the talent, the Fayth where removed from their resting places in the castle and placed in temples throughout Spira and Zanarkand. I am not quite certain of their locations as some of the temples have been lost but I do know that the Fayth once known as Lady Ravenclaw resides in the temple on the Island of Besaid, far to the south. I believe many of your companions come from that Island." On that count Harry knew Maechen was right. With the exception of Tidus, Rikku, Kimahri and himself, the majority of the people he was traveling with did indeed come from that island. The other news about Rowena Ravenclaw didn't seem half as astonishing as one would have thought. Harry had already had his suspicions when he discovered the Aeon more commonly known as Valefore, since it was a smaller, but almost carbon copy of Athena.

Harry gave him an absent minded thank you and moved over to the area where some of the guardians where already sleeping and lay down near an already snoring Tidus. He'd exhausted himself, staying in his Animagus form for most of the day. Even so, he still wore the small, satisfied smile that had resulted from his flight.

As the night drew on, the Summoner tuned out the world and let the tranquil aura of the Calm Lands lull him to sleep.

"AGGGGGGHHHHHHHHHHHHH!"

Tidus was once more sent violently to the world of the waking when a great scream rent the air from nearby, completely shattering the dream he'd been having, just as it was getting to the good bit. Blue eyes where nearly glowing as he glared around the tent looking for the culprit only to have his gaze settle on the tarred and feathered form of Wakka as he tried to hop outside, only to he hindered by the blanket that had been glued around his legs tighter than a mummy's bandages.

"I'M GONNA KILL YOU!" The red head threatened loudly as he took another spill that knocked the wind out of him. Giggling laughter sounded from outside as Wakka pulled off his pants to get free and tore out of the tent screaming bloody murder. The occupants of the tent who had cringed away from the sight of Wakka in his boxer shorts all rushed out to see the red head stomping after the prank players as they sprinted across the vast grasslands in different directions. Harry was running with his normal unearthly speed in the direct line of the red head, slowly slowing down as the effort of running and laughing so hard caught up with him. Tidus was ready to intervene when Auron shook his head and nodded to one side.

Rikku came running out of nowhere and knocked into Wakka, sending him sprawling in the dirt. The red head climbed back to his feet and glared at her only to notice the necklace dangling in her hand. He felt for the chain on his throat and his eyes widened comically when he realized it was in fact his necklace and charged like a bull in a shop full of red china. Rikku shrieked and ran off, zigzagging out of the way of his reckless lunges back toward the outpost where she threw the necklace to a very surprised Yuna before continuing past. Yuna held up the necklace to look at it and giggled, drawing Wakka's attention. The Blitzballer didn't seem to care she was his Summoner at the moment and came after her with not so nice intent. Yuna gave a delighted shriek similar to Rikku's and ran as fast as she could in the other direction. Tidus didn't really register that he had more company until Kimahri spoke up from beside him.

"Yuna happy, Kimahri glad." While Auron and Oa'ka had seemingly identified themselves with Lulu and the eldest of the groups, Tidus was fast starting to consider the blue Ronso as more than just a passing acquaintance, if not a friend. They'd come to somewhat of an understanding due to the people they'd sworn their lives to protect. The blonde didn't take his eyes off Harry as he nodded his agreement. Seeing the green eyed Summoner laughing over the apparent shock he'd received yesterday was a sign that he would soon get over it. Rikku had joined him sitting the knee length grass and they where both enjoying the sight of Wakka casing Yuna. When their third conspirator, Gatta plonked down beside them, absentmindedly picking a feather out of his hair and letting it go to swirl away on the breeze Tidus just knew they'd orchestrated this outcome from the word go.

A minute later however, everyone was startled by a shout and Tidus nearly jumped out of his skin when Kimahri growled loudly. The blonde followed his gaze and found Yuna sitting on the ground in front of a robed priest that she'd bumped into while running from Wakka. Her Guardian's converged of her position before Lulu spoke out in surprise.

"Father Zuke!" All eyes traveled up to examine the man in Yevonite robes. He in turn was looking down at Yuna who was climbing to her feet and backing up slowly.

"You know him?" Auron asked the black mage, an eyebrow raised, Lulu blushed faintly.

"Before Wakka and I were Guardian's to Yuna, we guarded Father Zuke. He gave up being a Summoner when we reached the calm lands and we returned to Besaid." Wakka backed away from the preist, his face going red as he retreated behind Lulu, somewhat covering his state of dress.

"It was kinda a short pilgrimage, ya know?"

"Then why is 'e all the way out 'ere then?" Oa'ka sent the man a mistrustful look. Father Zuke looked at him with sparkling eyes that reminded Harry of Dumbledore.

"I wanted to come see the so called 'Traitor' for myself." He explained, his eyes drifting to Yuna before scanning the three teen's sitting in the grass not far away. "But you certainly don't look like the Murderers of Maester Kinoc."

"WHAT?" Tidus took a step forward to join the conversation. Zuke looked momentarily startled before he gathered his wits again and gave them a grave look.

"Maester Mika just issued a personal order, you know. It said that Summoner Yuna, Summoner Harry and their guardians where the ones to murder Maester Kinoc and flee Bevelle. We are to kill you on sight… or so it says."

"What of Bevelle." Auron asked as Tidus stormed off in a temper, making his way to Harry, Rikku and Gatta to tell them the news.

"It looks calm on the surface, but there is great unrest beneath. After the death of Maester Kinoc, Kelk Ronso also left Yevon." There was a somewhat saddened air to the conversation after that.

"Convenient." Auron bit out in his normal blank tone. "Getting around will be easier with Yevon in disarray." He was right and no one there was going to challenge him on it. After a short while Father Zuke heaved a sigh, quickly figuring that his presence was no longer welcome.

"Be careful my friend's," he cautioned in a low almost weary voice. "You have been branded enemies of Yevon. You should avoid temples for the time being."

"Uh, Thank you, Father Zuke… for the warning." Yuna gave one of her deeper than nessesary bows. Zuke just waved it off as nothing. Lulu looked rather put off by something.

"Father, you came all the way here just to tell us this?" The old man gave her a shadow of what could be considered a cheeky smile.

"To tell the truth, I was a little curious to see this Summoner you are guarding. I hope her pilgrimage goes well. For your sake, too." He made no mention of Harry. "Well then, I must be off." He raised his hands and performed the prayer finishing in a bow. "I shall pray for all of you." Lulu and Yuna returned the gesture, making Wakka squeak as his cover shifted and with one last short laugh Zuke turned and left for home.

The other guardians just looked at each other and then between the Summoners before heading in to pack away their gear. The news from Bevelle had left them with a new shadow hanging over them, an unpleasant reminder that things weren't always going to be so easy going. Even so, they set out around mid morning, heading northeast toward the other end of the Scar where it was safe to cross. After only an hour or so of walking or riding Harry began to doze off as the peaceful air got to him. The others took him from his Chocobo and Tidus transformed, lumbering easily along the ground to keep the slow pace.

Harry meanwhile, dreamed.

"Hey Harry, you look dead tired mate. You should come down and rest." Harry stared at Ron blankly for a second before replying.

"I'm not tired." The red head let out a bark of laughter that said clearly that he didn't believe him.

"Yeah right, Harry! If you keep pushing yourself like this you'll burn yourself out, then 'Mione will get mad and you know what she's like when she's mad. She'll say "You can't save the world if you can't save yourself." Harry gave Ron a deadpan look.

"I'm sleeping now aren't I?"

It was true. The dark ethereal quality of the caves he sat in could only be found in a dream. Ron looked around again and shrugged.

"Who knows." Was all he said sitting back cross-legged on the large glowing orb of amber that held an ancient looking Samurai outfit in its depths. A ghostly dog trotted around the back of the cave and lifted its leg against a wall, totally unconcerned by its surroundings. Harry crumpled his nose.

"Snuffles!" The grim like dog gave him a doggy grin, completely unashamed and continued to stray. He turned back to Ron to find his old Guardian staring at him almost calculatingly, a look that wasn't often seen on Ron's face outside of a chess match.

"Who's caring for you now?" He asked taking in his appearance. Harry was startled for a moment, wondering what to tell him but instead he just settled on the truth.

"I have a few Guardians." He admitted. "But the one who's been with me from the beginning is Tidus." Ron raised an eyebrow. It seemed in his dreams this Ronald Weasley wasn't so hot headed. Nonetheless Harry understood the silent request to elaborate.

"I met him before I arrived in Spira." He explained. "When I appeared in Zanarkand. Tidus says that I appeared out of nowhere and landed in his lap, literally! He took me to see a Blitzball game as well before Sin attacked and destroyed everything. Auron seemed to drag us along, and next thing we knew we where shivering on a rock in the middle of nowhere." He trailed off slightly and gave a hazy kind of smile. "He's a natural Animagus, you know." He added after a moment on silence.

"A great big golden dragon… it suits him to. He has a lot of power and he's always there. I don't think he's ever left my side of his own free will since we got here and now… I think I've fallen in love with him." Both of Ron's eyebrows went up this time.

"You've got it bad mate." He huffed out with a shake of his head and Harry gave him a sheepish smile. The news that Harry liked guys was nothing new even so his expression took on a concerned cast. "You said he came from Zanarkand." He clarified getting to his knees and shuffling right to the edge of the amber orb so he and Harry where face-to-face.

"You have to know." He began slowly. "Harry… Tidus isn't real." Harry acted almost like he didn't hear him until the meaning of the words sunk in and he found himself staring at Ron in disbelief.

"What?" He asked softly. Ron gave him a pitying look.

"Your guardian… isn't real… We called his father to the real world from the dream ten years ago in the hope that he could free us from Sin and Yu Yevon. But he failed and now we've brought Tidus. He was only a handful of thoughts and memories left over from the true destruction of Zanarkand that we saved within an eternal dream, but he won't be able to stay in the real world much longer. When Sin dies, he will fade." The youngest male Weasley looked down at his hands so he wouldn't have to see the growing look of horror on Harry's face. "We are tired of dreaming Harry. We can't keep dreaming forever, it's time to sleep, but as long as Sin is still here we can't…"

Harry didn't quite know whether it was the dream getting fuzzy or his own watering eyes that made it so difficult to see Ron at that moment.

"We're sorry Harry." Ron said apologetically, but Harry wasn't listening. His fists where clenched in his lap while his whole body shook.

"I'm not… I'm not going to let him fade."

"Harry!"

"Harry!" The dark haired Summoner groaned as he opened his eyes and stared blearily at the dark silhouette of the person who stood over him, framed by the sun. Grasping the scaled surface beneath him he pushed himself up and shook his head to clear it.

"Rikku?" The younger blonde girl gave a little sigh of relief and reached out a gloved hand to pull him to his feet.

"Yay! You're awake! For a moment there it didn't look like you where going to and Tidus was getting all panicky 'cause he was growling and stomping so we woke you." Harry blinked at the rambled speech and took the opportunity to look around at the surroundings.

"Where are we?" He asked thickly as Rikku helped him slide from Tidus's expanded back.

"We've reached the way out of the calm lands, we 'ave." Oa'ka explained with a careless air as he walked over, they where at the foot of the cliffs that surrounded the grasslands to the northeast. With the sun high in the air, the shadow of the cliffs didn't spread so far. "There's a ravine on the other side of that there pass an' it's the only way te Mount Gagazet. Though, this lad wouldn'ta fit as a dragon." He said gesturing to Tidus as he reverted to human and strode over the short distance created by the displacement of his mass. Harry saw the faint strains of worry in his expression and remembered what the Ron in his dream had said.

"Your guardian… isn't real…"

He lowered his eyes to the ground and cursed his old friend and guardian to hell and back for making him doubt.

"You have to know."

"We're sorry, Harry."

Ron, he knew now, was one of the Fayth. How he had become one, why he had become one and when he had become one where all mysteries but Harry couldn't bring himself to doubt the dream. It had all seemed to real and somehow it was confirming what he'd felt in the back of his mind all along. His time in Spira, even if half of it had been spent on the run or caught up in politics, had just been to good to be true. He was faced with the dilemma of deciding between two very different outcomes. On one hand, he could help the Fayth defeat Sin and loose the one person who meant more to him than anyone in this world or out of it, or he could turn around now and forget about Sin, sabotage the chances of the other Summoners and selfishly keep his happiness while the world was slowly destroyed.

But, in this case there really wasn't a choice.

His pride and his Hero complex wouldn't let him leave the problem to sort itself out. Now that he'd walked among the people of Spira he didn't want to leave them to Sin's mercies and he was sure every single one of his guardians felt the same for many different reasons. They had been bound to this fate the moment Harry had dropped out of thin air into a dream then out of it.

He had to fight the urge to just start crying.

"Are you alright?" Tidus asked, still somewhat frantic as he pulled him into a hug. Harry let his limbs hang limply by his sides and closed his eyes, leaning heavily against the blonde's chest.

"Yeah." He managed to mumble out. "I'm fine, just tired." The voice of his own sub-consciousness didn't agree with him in the slightest.

'Liar'

Harry gave it the mental finger as they began to walk into the shadows.

'I'm not going to let him fade.'

A/N: This looks like as good a place as any to leave off. I was going to make it longer but I thought you lot would actually prefer and update as opposed to no updates for a while longer… (Did that make sense to you?)

Anyway…

Don't forget to review!

Cya!

EXTRA!

Magic of Spira part 2!

Black magic!

Black magic is basically any magic that can physically harm or impair the person it's cast upon. There is a wider variety of spells and this isn't always restricted to the black mage's like Lulu and Oa'ka who specialize in it.

First there are elemental spells starting with the four basic elements, Fire, Ice, Water and Lightning.

Fire – First level fire spell

Fira – Second level fire spell

Firga – Third level fire spell

Water – First level water spell

Watera – Second level water spell

Waterga – Third level water spell

Blizzard – First level ice spell

Blizzara – Second level ice spell

Blizzaga – Third level ice spell

Thunder – First level lightning spell

Thundara – Second level lightning spell

Thundaga – Third level lightning spell

After these are the non-elemental damage inflicting spells.

Bio – Poison's people

Break – Turns the enemy to stone

Demi – Reduces the enemy's current health by a ¼

Death – Causes an instant knockout for some enemies

Doom – Starts a countdown of turns till Death is cast on a character

Drain – Drains the health of an enemy and gives it to the caster

Osmose – Drains the magic of an enemy and gives it to the caster

Flare – Causes large amounts of non-elemental damage on an enemy

Ultima – Causes fatal amounts of non-elemental damage on an enemy

There are other black magic spells motioned in other final fantasy games but these are the ones most relevant to Final Fantasy X. Also, as far as Harry's magic is concerned, things like Charms, healing and all that would be considered White, while Hexes, jinxes and curses, etc would be considered Black.