Lethe, Underworld:

3rd Person POV:

As the light of the teleportation crest died down, Theo blinked a few times to reorient his vision before his eyes widened at the sight in front of him.

"A beauty, ain't she? Say hello to one of the Five Rivers of Hades and the location of your first trial, Lethe." Oceanus said with a grand flourish aimed at the flowing river in front of them, the water an abyssal black with green blots of light here and there as Poseidon smiled.

"It's been a while since I've been here and its presence is still as strong as ever." He said with a smile, Theo's shock growing as he only now felt the pressure emanating from the river.

"It's incredible." He muttered, to which Oceanus and Poseidon both chuckled and nodded as Khione rolled her eyes.

"Enough with the theatrics or else, we're going to be here for the next decade. Tell Theo what he should do."

"Always spoiling our fun." Oceanus grumbled, Khione just rolling her eyes as Theo snapped out of his shock.

"The trial is simple: A dive of faith." Poseidon said with a smile, with Theo just raising an eyebrow.

"And by that, you mean…"

"I thought it was obvious. Dive headfirst into the water, touch the bottom and come back up when you're done."

"And how will I know I'm done?" Theo asked with a frown, Oceanus just smirking as he shrugged.

"I don't know, because we never had to take the Trials. All I can say is what the other children of Poseidon told me. 'You'll know when you're done'." Theo just groaned at that before he nodded, walking towards the river bank before he raised an eyebrow at the sight of the water stilling.

"Don't worry. That just means they know you're here for the trial." Poseidon said from behind them and he turned back before giving them a deadpan stare as Poseidon, Oceanus and Khione had decided to take a far step into the background.

"Oh, don't worry about this. It's just a necessary…step." Khione said with a convincing smile, Theo just rolling his eyes before he shook his head as he turned back to the river. The water had now gone from still to raging, flowing rapidly as the green blots of light glowed fiercely.

"…This is a bad idea.." Theo muttered to himself before taking a deep breath, letting it out slowly before diving headfirst into the pitch-black river.

All around him, he felt nothing but the force of the river trying to push him along, but he fought against it as he swiftly dove towards the bottom of the river, only to find that it was deeper than he thought as he swam for what felt like minutes before letting out a sigh of relief as he caught sight of the bottom.

Twisting around, he landed feet first on the bottom and was about to push off when he felt his body lock up completely, unable to move a single muscle as he felt his feet sink into the bottom.

Flicking his eyes around frantically, trying and failing to move even a single muscle, his eyes widened as the green light all conjoined together in a bundle in front of him, the light transforming into the visage of a beautiful long-haired woman with a soft smile and barefoot as she was dressed in a flowing green dress.

"Hello, young Theseus. It's a pleasure to see you again." Theseus frowned at that as he couldn't recall meeting the woman at any point in his life before his eyes widened.

"L…Lethe?" He asked, shocked as the woman smiled and nodded.

"Yes, that is my name, Lethe, and I must say, I did miss hearing you say that."

"You speak as if you know me." He said and she giggled as she nodded.

"I did indeed. From the first time you came here to perform the Trials to the last time you arrived."

"My past lives. All the Theseus throughout history have all undertaken the trials, haven't they?" He said with a smile, to which Lethe gave a sad smile as she nodded.

"Yes. Fifteen Theseus have undergone my trial and all fifteen have passed but every time I think that they're going to make it, I'm saddened to see another one arrive here just a decade or two later." She said with a sigh, Theo frowning before he sighed.

"I'm sorry for that, but don't worry, this time I won't fail."

"That's what they all say." She said with a sad smile, Theo smiling back before he shook his head.

"Enough with the sad stories. What am I supposed to do for the first trial?" He asked and Lethe just smiled as she held out a hand, confusing him.

"The first trial is the easiest. Grab my hand and relinquish all of your powers and potential to me."

"…Everything?" Theo asked in shock, Lethe giggling as she nodded.

"Yep, you're definitely Theseus, because you have the same reaction every time. Yes, everything. Your water manipulation, your quake powers, your lordship over water and all marine life. Everything. When you relinquish everything that makes you Theseus, you are shown who you truly are."

"And…what if I don't?" He asked with a frown, to which Lethe just snapped her fingers, Theo's eyes widening as the green glow surrounding Lethe brightened up the abyssal black water to reveal a sea of horrendous aquatic abominations swimming around them, all snarling as soon as the light touched them.

"These are my children, the Leviathans. They left you alone because you were coming to meet me, but if you don't wish to undergo the trial, you'll have to swim back up while fighting for your life." Lethe said with a smile, the Leviathans all looking as one at Theo before swimming along as the demigod sighed and shook his head.

"Damned if I do, damned if I don't, huh?" He muttered to himself, Lethe smiling as she shrugged before holding out her hand once more. Theo just stared at the hand before he sighed and grasped it, a bright green orb appearing at his chest before it travelled down his arms and into Lethe's body, who raised an eyebrow as the orb travelled up her arm and into her chest.

"You are definitely far stronger than most of your past lives, so perhaps this time, you might be able to complete the Trials. Now, go and if you do finish the Trials, come and see me." She said, Theo smiling as he nodded before she snapped her fingers and instantly, he went from staring at Lethe to staring at the top of the river, his eyes widening as Poseidon appeared next to him with a relieved smile.

"You passed. Congratulations." He said with a smile and Theo finally noticed Khione's arms wrapped around his body in a tight hug as well as the freezing chill spreading through his body.

"U-Uh, G-G-Grandmother. A-A b-bit cold, d-don't you think?" Theo stuttered out, Khione's eyes widening as she quickly pulled back her chilling aura as well as stood as far as away from him as she could.

"Oh, I'm so sorry, sweetie! I guess I'm grown used to you liking my cold." She said with an apologetic smile, Theo smiling as he hugged her softly.

"It's okay, Grandmother. I didn't think that they would take away my cold abilities along with the rest of my abilities."

"That is strange, because usually, Lethe only takes the abilities you get form being my son." Poseidon said with a frown, Theo shaking his head as he let go of the now-calm Khione and turned to his father.

"I should have expected it since she did say she was taking all of my abilities." Theo said, Poseidon's frown deepening before Oceanus spoke.

"How do you feel?" He asked, Theo staying silent as he clenched his feet and frowned at the utter weakness of his grip compared to what he was used to.

"Like utter shit." He said, Khione frowning slightly at his language as Oceanus nodded.

"That's what happens when every bit of your demigod essence is taken away and you're left only with your mortal shell. Now, let's move onto the next one." He said and before Theo could speak, a teleportation crest appeared under them and took them away, Theo's eyes widening at the frozen wasteland appearing around them before he shivered at the chilling wind blowing around them.

"Welcome to the location of your second trial and known as the 'River of Lamentation and Wailing', Cocytus." Oceanus said, gesturing towards the dark blue river flowing slowly in front of them as well as the sight of millions upon millions of frozen corpses all sitting next to the river.

"If you wish to pass this trial…"

"Let me guess, jump in and head to the bottom?" Theo interrupted with a wry smile, Oceanus chuckling as he nodded.

As Theo took a deep breath and started walking towards the river, he was stopped by Poseidon placing a hand on his shoulder, turning to see his father giving him a concerned stare.

"Listen, this trial is where most of your previous lives failed. Just remember, no matter what happens down there, we'll always love you no matter who or what you are, okay?"

"I know, Dad." Theo said with a smile, Poseidon smiling back before letting him go as Theo walked to stand right next to the river bank.

'Let me go, please.'

'I don't deserve this.'

'It wasn't me. It was them.' Theo raised an eyebrow as he stood next to the river bank, his hearing flooded with voices coming from all sides and it sounded as if they were all sad and regretful about something that happened to them.

'Or, they're lamenting their mistakes.' He realised, looking around and his thought confirmed as he heard a few mutter about the few mistakes they could have avoided or the fact that some of them did something they now regret.

"Just dive to the bottom and swim back up…without my powers. Just a leap of faith." Theo muttered to himself with a sarcastic smile before taking as deep of a breath as he could, crouching before leaping headfirst into the river.

'This is fucking hard! Why do people swim if they can't breathe underwater?!' Theseus shouted in his mind as he bolted towards the bottom, now regretting having to give up on his powers as he swam as fast as he could.

Theo then smiled triumphantly and thanked his lucky stars that Cocytus' bottom was not as deep as Lethe's as he flipped and landed on the bottom, pushing off the bottom and swimming towards the surface before his eyes widened as he finally realized the chilling cold of the water around him.

Even as he swam frantically, he could feel the cold invading his body and slowing it down, his eyes widening as a bony clawed hand appeared behind him and grabbed his ankle.

Kicking down a few times, he managed to get the hand off and tried swimming back before he gasped as another clawed skeletal hand wrapped around his throats, dozens of others appearing from the dark blue waters around him.

The hands clawed and grasped at his thrashing body to pull him back into the river, Theo failing to fight them off as he struggled vainly to reach the surface.

'No! No! I want to live! NO!' He shouted as he clawed at the water, feeling his consciousness slipping and his body slowly down as the cold was now too much to bear. The icy cold water flooded his lungs and made him gasp and choke for air, clawing at the hands wrapped around his throat before he finally felt his limbs go slack.

'I guess…I wasn't meant to live. Sorry, Dad. I…I couldn't live up to your expectations and become King of Atlantis. Sorry, Mom. I guess I won't get to eat your salsa again. Sorry, Grandma. I guess you're going to have to look…for another snowflake to look after.' Theo thought with a resigned smile as he felt the skeletal hands drag him towards the bottom, not feeling any emotions as they placed hm down softly before disappearing. As his corpse laid at the bottom of the river, a dim blue light appeared in the water next to it and spoke.

"I thought you were going to be the same as the others, but you're one of the few who regrets not living up to the expectations of those around him instead of thinking you're too strong to die here. I, Cocytus, hereby allow you to pass my trial. Well done, young Theseus." The light said before it disappeared and Theo gasped as he awoke on the shore and bolted upright, his eyes widening at the sight of Poseidon looking relived before hugging him tightly.

"You're okay, my son! You're okay." He whispered, Theo's eyes widening as he also saw Khione hugging him before turning to the smiling Oceanus.

"To pass the second trial, you must die as a mortal and Cocytus will judge you whether you're worthy or not on being brought back to life." His eyes widened at Oceanus' explanations before he frowned as he turned to his father, who had let go of him.

"And that's why you said that to me?" Theo asked, Poseidon sighing as he nodded.

"The reason you failed in most of your past lives is because of the fact that most of those times, you thought you deserved to become a God instead of realising that Godhood is only granted to those who deserve it." He said, Theo sighing as he stood up with Khione still hugging before he smiled as he hugged her back.

"I don't think my heart can handle this." She muttered, to which Theo chuckled as Poseidon smirked and Oceanus rolled his eyes.

"I told you that you wouldn't want to watch, but you didn't listen, so now, you're going to have to suffer." He said with a shrug, Khione giving him a glare as Theo chuckled.

"I'm okay, grandmother." Theo said, Khione giving him a soft smile and a quick kiss on the cheek before letting go with a sigh as Theo grinned at Oceanus.

"I'm two trials down and three more to go. Where to next?" He asked, Oceanus grinning before their surroundings changed and Theo gasped as he was hit by a wave of scorching heat blasting him in the face.

"Phlegethon never changes, huh?" Poseidon said with a grin, Theo staring at the lake of bubbling magma in front of them before turning to Oceanus with a death glare.

"I am NOT jumping in there." "It's easy. Imagine that the magma is just warm water and just jump in. Besides, this one is the easiest of the trials. It's just swim to the bottom and-!"

"And back up? Yeah, you said that about the last two and I had to deal with ghost hands dragging me back to the bottom and a goddess & her leviathan children stealing my powers." Theo said, to which Oceanus stared at him before Theo's eyes widened as he grabbed him by the head.

"Dad! Help!"

"Sorry, son! Fortune favours the bold!" Poseidon shouted back with a smile, Theo giving him a betrayed glare before he gave a pleading stare to Khione, who smiled and waved.

"Have fun, sweetie!" She said, Theo glaring at her before his eyes widened as he felt the air around him pop and his body going lifeless, glancing down to see nothing but scorching magma underneath him.

'It's warm water! It's warm water! It's warm water! IT'S WARM WATER!' Theo shouted in his mind as he took a deep gulp of air and braced for the heat, falling feet first into the water and surprised to feel himself sink into the magma and…nothing.

Was it hotter than normal warm water? A bit yeah, but other than that, he didn't feel anything detrimental to his body.

'Okay, so they weren't lying about the heat but who knows what's in here?" Theo thought to himself with a frown as he swam towards the bottom of the lake, surprised to swim head first into the bottom of the river.

Rubbing the top of his head with a silent grumble, he turned and swam back up, breaking out of the surface just a few moments later before swimming to the shore where a smug Oceanus was grinning at him as Poseidon and Khione looked amused at his glare.

"I hate all three of you." Theo grumbled, Oceanus chuckling as he tapped his fishing spear against the ground and the magma disappeared off of Theo.

"I told you it was just a simple dive to the bottom and swimming back up." He said with a smile.

"Oh, please forgive me doubting you." Theo said sarcastically, Oceanus chuckling as he nodded and patted him on the shoulders.

"You're forgiven. Now, this next one is where you fail every time, so I'll be heading there alone with you. Khione, Poseidon, anything you want to say in case the brat doesn't make it?"

"No, because I have the utmost trust in him returning." Poseidon said with a smile, Khione nodding as Theo smiled and nodded

. "You said that about the five few that made it to this point as well and look how that turned out." Oceanus said bluntly with a shrug, Poseidon glaring at him as Khione sighed and Theo chuckled.

"Don't worry, Father. I'll do you proud."

"I already am." Poseidon said with a smile, Khione walking forward and giving Theo one last hug before standing back as Oceanus went to stand next to him.

"You ready, Theseus?"

"As I'll ever be." Theo muttered, Oceanus chuckling as he tapped his spear against the ground and they teleported away.

At the same time:

Yamamoto Manor, Neo-Kyoto:

"You actually want to finish your trials? And here I thought my darling great-great-granddaughter was just a simple woman who wanted to be a mother." A beautiful red-haired woman said with an amused smile as she sat on a stack of cushions, a red yukata covering her body and nine crimson furry tails spread out behind her as Yasaka sighed.

"Tamamo-baa-chan, please teach me how to use Zetten." Yasaka pleaded, Tamamo staring at her descendant before sighing as she placed her pipe down.

"Fine, I suppose since you asked so nicely, I'll teach you, but remember, you struggled to use it before, so don't be mad at me if you can't." Tamamo said as she stood up, Yasaka nodding before her eyes widened as she dove out of the way and out towards the courtyard, a flying slash cleaving through the air of her previous location and dissipating on contact with the walls as Tamamo cackled while following her out.

"What better way to teach you than by hitting you with it over and over again?!" She exclaimed as three of her tails whipped forward in a frantic flurry, Yasaka's eyes widening at the sight of the dozens of air slashes flying towards her before her tails unravelled and she bolted forward.

At the same time:

Fields of Freyja, Asgard:

"So, you wish to finish your training?" Gondul asked Rossweisse, who nodded as runic sigils appeared around her. They were standing on grassy plains just on the outskirts of Asgard, both ladies clad in their Valkyrie armour though Gondul's armour was more conservative.

"Yes! I wish to use the Mistelteinn Wand." Gondul raised an eyebrow at that as she smirked.

"I see. This boy must mean a lot to you if you're willing to go that far, doesn't he?" Gondul said with a knowing smile, Rossweisse blushing with a smile as she nodded.

"Haha! Fine then, my dear barnabǫrn. Let us not waste any more time!" Gondul exclaimed as she snapped her fingers, Rossweisse's eyes widening at the sight of a sea of light blue serpents sprouting from the ground and slithering towards her before she began firing spell after spell.

A/N: And there we go! Another chapter, another day!

Next chapter, the final two trials and an awaited battle!

As always, read, enjoy, review and until the next one…

Ba-Bye~!