Being partially immortal took time, and training to get used to. But eventually, Percy grew accustomed to it. He spent the next 80 mortal years training. During that time, the mortal world grew. Their first civilisations began to appear around the world. The gods showed themselves to the Greek world, and Percy was introduced as the envoy they would use for any specific orders from Olympus. He had yet to have a message to deliver, but that was soon to change. A few days ago, Hera and Zeus had their first child. Ares. A god, yet to receive his domains, but when it happened, it would be down to Percy to announce the same to the mortals, before Ares was presented to them. This brings us to where Percy is now, training with said God, currently close to his physical age of 17.
If Percy had to risk a guess, he'd suspect Ares was a combat god of some kind. The sheer aggression and raw strength he showed were staggering. Percy was attempting to help 'train' Ares, but that was difficult when Ares seemed to scorn any and all kind of tactical thought in combat, preferring to throw his full strength at his opponent. Being a god that would work against most opponents. Percy was not one of those opponents.
As he had come to expect, Ares charged at him like a raging bull, before raising the greatsword above his head with both arms, leaving his chest wide open. Percy could have cut him in half if it was a real fight but decided to go for the embarrassment route. As Ares brought down the massive blade with a yell, Percy spun to the side. The blade shattered the arena floor, sticking cleanly into it. Percy dug a shallow cut into his opponent's side, not aiming to hurt the young god too much. He was trying to test Ares' endurance, with how ridiculously aggressive Ares was, he wanted to test his stamina. Ares bellowed in rage once more, before he Ripped his blade out of the ground, sending chunks of the floor into the air, making a wild circular cut with it. Percy ducked under the blade just in time, hearing the shink of the blade slicing the air above his head. This was going a bit too long now; he was starting to get tired out and didn't want to risk getting hit because he was slower than usual. He quickly hopped backwards and began to circle Ares. This time, his opponent took things slower. Slower by Ares' standards was what any other fighter would describe as holy gods that's aggressive. He charged forward, this time keeping his guard up. He made a powerful swing, which Percy parried, using the opening to quickly drop his sword, confusing the hell out of Ares, an opportunity he used to deck him in the mouth with a gauntleted fist. Ares staggered backwards, and Percy summoned Storm hunter to his hand and pressed it up against Ares' throat.
"Dead"
"…Fine. Why are you so good at this again?"
Percy dissipated his blade and armour before picking up a large water jug, pouring half of it over himself and drinking the rest
"Ares, I've had 80 years on this earth where I did practically nothing but train. You are 2 years old. You aren't going to be beating me in a direct swordfight, especially not before you get your godly abilities."
Ares nodded, before putting his great sword back on its rack.
"Percy?"
"Hmm?"
"How was it the first time you met mortals?"
"They're…. different, Ares. Although I'm not the best person to ask. I'm still half mortal you know. You're a full god, and you'd do well to remember that."
Ares, for the first time in as long as Percy had known him, looked thoughtful.
"You'll know for yourself soon enough. You get your domains and titles tomorrow, and then I take you to meet them."
2 days later
"The god of war huh? Can't say I'm particularly surprised, you were damn good with a sword from the start."
"Thanks, I think. How is this meeting the mortals thing going to go again?"
"Your father has sent an order through all the prophets, for all of them to gather in the heart of Greece. They will be there soon. When they arrive, I go down there and explain the situation. When I announce you, you flash in, state your domains, they might have questions, and then we leave. Should be straightforward."
The two waited in comfortable silence until Percy felt a gentle push in the back of his mind, before hearing the voice of his uncle
'The mortals have arrived, Perseus. Go now. Call for Ares when you have explained everything to them.'
Percy stood up and cracked his neck.
"Aright, show time. I'm heading down. I'll call for you once I'm done telling them about you."
Ares merely nodded, tapping his foot slightly as Percy dissolved into a fine mist.
As the immortal Demigod appeared in front of the gathering of mortal priests, all the small chatter that had arisen died out instantly, and all eyes turned to him. There was a brief moment of shock and contemplation, before the priests all bowed, which slightly annoyed Percy, even though he had been expecting it.
"Save your bows for the gods. I am simply a messenger here."
As the priests all rose and faced him, Percy took a breath and spoke.
"I am certain you are all wondering why you are here. I shall keep it short. There is a new god upon Olympus."
As soon as the words left his mouth, the silence was broken by murmurs of shock and surprise. Percy waited a moment for it to die out, before he continued.
"Today, it is my honour and duty to introduce to you, Ares, god of war, bloodlust, and courage."
With a flash of blood-red light, Ares appeared next to him. The Mortals all fell to their knees in a bow. Ares looked slightly uncomfortable, but steady nonetheless.
"Today you see the newest member of the Olympic council. You will soon receive word from the gods regarding Ares' Symbols, and how he is to be worshipped. For now, return to your cities and inform your people of the new god. You may leave."
Percy turned to Ares and flicked his head, and the two disappeared.
As the years passed, more and more members joined the Olympian council. Over the hundreds of years, Percy had gotten close enough to some of the younger Olympians that he felt he could call them friends. He had, after all, spent close to centuries with some of them. Then, the age of heroes began. Percy was himself a demigod, and now his kind was rising to the forefront of the world. The first of these Legends that Percy encountered was named, strangely enough, after him.
When the boy was going to hunt down Medusa (Percy was still mad at both his father and Athena for that. He had refused to talk to either of them for 11 months, and then beat the snot out of both of them in spars for another 3.) Percy was tasked with delivering a bag of gifts from Athena to him. Should it technically have been Hermes? Sure. But where demigods were involved, he was considered the expert.
He was waiting around an area that he knew for a fact the boy would pass through, his body dispersed into water vapour around the area. As the hero walked past, he reformed himself a few feet in front of him. After a brief, nearly imperceptible by mortal standards, pause, The hero drew his blade, pointing it at his namesake.
"Who are you, and where did you show up from?"
Percy chuckled. "You'd think you would recognize your own namesake, but I suppose you don't"
It took a moment for the hero to process what Percy had said before his eyes widened and he fell to his knees
"Forgive me, milord. I meant no disrespect."
"You forget that I am a demigod just as much as you are, Perseus. You have no need to bow to me, as much as the gesture is appreciated."
The child slowly, and rather unsurely, rose to his feet
"Why are you here, milord?"
"Olympus wishes for you to succeed. The gods themselves may not directly render you aid, but they send you gifts. They thought it would be easier for you to process a demigod's presence than that of a god."
With that, Percy tossed a small sack at the boy, who caught it with a small grunt.
"That contains all the tools you should need to destroy my father's great mistake. I wish you luck, boy."
"Milord, if I may?"
"Hm?"
"You said the gods are unable to aid me themselves, but you… you being a demigod, could you not slay the beast yourself?"
"Oh, I most certainly could boy. But then how would your legend be made?"
Percy flashed him a grin, before dissolving once more into a fine mist, and hanging about a bit behind the boy, watching him. If it seemed like he was going to fail, Percy would step in, not content to leave the boy to his death. Thankfully, he didn't need to.
What he wasn't expecting was for a horse and a shiny golden dude to pop out of medusa's neck. The golden man hurled himself into the ocean, but the horse, who for some reason had wings, began to fly. Percy had half a mind to follow it but was more concerned with the newly christened slayer of Medusa. He entered the cave to see the boy shove Medusa's head into the sack, before cracking his eyes open.
"Good work kid. But I think you forgot to consider her sisters."
Perseus whipped around in shock, seeing the two other gorgons baring their teeth and ready to charge, before one of their heads was lopped off their shoulders, and the other had a hand through its chest, as Percy crushed its heart.
"Technically you were only told to kill Medusa, so me killing her sisters didn't affect that did it? Congratulations Perseus, slayer of the Medusa. Return to your kingdom and claim your throne."
Percy appeared back in Atlantis with a small smile on his face. The kid was named after him? He was honoured as all Hades but also found it strange that mortals held that much respect for him. He was, after all, only half a god. Maybe it was because he was the first half- immortal? He couldn't be sure. Artemis had been talking to him for some time about setting up a hunt for herself, which would contain maidens with immortality like his own. He liked the idea but was uncertain about Zeus. He had a feeling the lord of the skies wouldn't take the idea of that many immortals running around kindly. Then again, Artemis was his daughter. As he entered the throne room, he could tell his father was angry. Which normally meant a few busted ships and drowned mortals
"So, Amphitrite still giving you the cold shoulder?"
"It's not always about her you know"
"yeah, but it is most of the time"
"Not this time. Well not directly. That foolish queen, Cassiopeia, had the gall to say that her daughter was more beautiful than the Nereids themselves."
"How many harbours did you blow up?"
"None. I sent Cetus to destroy the place."
Percy froze for a minute. Cetus was an incredibly destructive beast. For a moment he felt his father had gone too far. But then he considered that the queen had knowingly scorned a god. That was something you simply don't do if you want to live.
"How much did you ask him to do?"
"Until they give me a reason to stop hi- "
Poseidon froze before he began to laugh.
"Mortals. They'll do anything to save their own hides, no matter how despicable."
"What are they doing now?"
"They're trying to sacrifice the girl to Cetus, in hopes that I will call him off. A bit far in my mind, since it wasn't the girl doing the bragging. Would you mind going and calling him off? I believe the arrogant queen has learnt her lesson."
Percy nodded and left, going to the city to call of the rampaging beast before it ate the princess. What he hadn't expected was to see Cetus, turned to stone, with Perseus the hero holding up medusa's head at it. As the boy put the beast's head back in the bag and turned to his namesake, his face turned white for a moment and he bowed once more.
"I am sorry milord. I could not stand to see this woman be killed for a crime that was not her own."
"Don't apologize. You merely did the exact same thing I was here to do. Really you just saved me the time."
Perseus let out a sigh of relief before turning to Andromeda and unchaining her. As Percy was preparing to leave, he heard a trumpet sound out, and the king and queen came to where they stood. At first, they completely ignored him, rushing up to the hero and showering him with thanks. Then the queen made her last mistake.
"Even the god of the seas himself cannot take you away, Andromeda! He must know I was right, your beauty surpasses that of all!"
Percy was behind her in an instant and had her by the throat.
"You, child, do not learn from your mistakes."
A dozen spears were pointed at him in an instant, and a dozen more blades followed. He dropped her and drew his own blade.
"You do not know who I am. So I will tell you. I am Perseus, the first Demigod. The son of the very god you so casually scorned, not 5 steps from his domain. Did you really think that would go well for you? You were so arrogant that you scorned him, and then tried to throw your daughter to her death rather than repent for your own error." He turned to the soldiers surrounding them, most of whom had dropped their weapons.
"I give you one chance. I will kill this proud fool now. If you interfere, you join her." The remaining weapons went down.
"wise choice." He turned to the king, who was trembling in his robes.
"In the future, choose your consorts more wisely."
He picked up Cassiopeia by the throat once more, before dissipating back to the ocean floor. If she had so much scorn for the seas, she would die by them. He watched as she desperately tried to get her bearings, to figure out what was up and what was down, as the pressure slowly crushed her to nothingness.