River of Acheron, Underworld:

Theo's POV:

Reappearing from the bright blue teleportation crest of Oceanus, I blinked a few times to get rid of the vertigo before I raised an eyebrow at the polluted river in front of us.

Its water was like that of black tar, bubbling and sticking to the river bank. The part that made me raise an eyebrow were the floating skeletal figures in the water who, while dead, were moaning and groaning in pain as they were carried down the river.

"Welcome to Acheron, the River of Pain and the location of your second-to-last trial." Oceanus said and I didn't miss the slight frown on his face as he spoke nor the slight undertone of anxiety in his voice as I turned to face him.

"Listen. This trial isn't just a swim to the bottom and back. This is where your willpower will be decided. Every person you have killed or have watched die in front of you will be watching and talking to you while you're getting to the bottom and back. Not just that, but the pain will increase the longer you're underwater, which means that you have to finish the trial as fast as you can while under extreme pain and hearing the whimpering and painful crying of everyone and everything you have ever killed."

"…So, nothing serious, huh?" I said with a shaky smile, to which Oceanus sighed as he patted me on the shoulders.

"If you want, we can turn back and get your powers back from Lethe. This is the place where you always fail, you always die. Not just you, but every demigod child of Poseidon that ever makes it to this point always dies." I sighed at that as I looked at the river before back at Oceanus.

"If I don't do this then all the preparation would have been for nothing. That and I could never go on living knowing that the opportunity to get stronger was here and I decided to throw it away." I declared with a determined smile, Oceanus just staring at me before he sighed and nodded.

"Fine, then. If you do make it, then you'll be the first to ever do so. Good luck, Theseus." And with that said, he stood back, giving me one final nod as I sighed and turned to the river. Walking to the river bank, I stared at the tar-like water before dipping a foot in, my eyes widening and pulling my foot out with a hiss as it felt as if needles were stabbing through my foot.

'That's…a lot more painful than I expected.' I thought with gritted teeth as I felt my foot cramp up, shaking off the pain before taking a deep breath.

"Just a leap of faith." I muttered to myself as I took a few steps back, letting out a sigh before breaking into a full sprint towards the river, taking in a deep gulp of air as I dove head-first into the water.

Pain. PaIn. PAIN.

PAIN!

PAIN!

PAIN!

As I sunk into the water, it felt as if needles were stabbing my body over and over as I dove deeper, gritting my teeth and swimming as fast as I could while stifling my groans as my muscles locked up.

You ripped out my heart.

You tore my child apart in front of me.

I watched my mother drown because of you.

My children were buried alive thanks to you.

Everywhere around me, I could hear the sound of thousands upon thousands of voices, all of the voices feeling as if they were whispering directly into my ears.

'Ignore them and keep goi-Arrghgh!' I stopped on the bottom and grit my teeth as it felt as if something just ripped out my liver, looking down to see my abdomen visibly rippling with pain.

Gritting my teeth until they bled, I pushed off the ground as hard as I could and started my trek back to the surface, not caring for the voices caressing me or the blood now flowing from my nose and eyes.

'Come on! Come on! Come on!' I shouted at myself as I slowly approached the surface, reaching to break it with a smile before my eyes widened as I touched a solid wall.

'No! No! No! No!' I pounded away at the wall as hard as I could, feeling my hope drain away as I barely dented it. Quickly looking around to try and find something to break the water with, I could barely see a few centimeters in front of me before I felt my body lock up in agony as the pain all but tripled.

'Not again! Not this time! What do I do?!' I quickly racked my mind on every word that Oceanus told me, trying to figure out the hidden meaning behind this test before an idea came to mind.

'I'm all out of ideas, so I guess this is the last chance.' I thought with a sigh before I opened my mouth feeling the black tar filling my lungs.

"Aaargaaghghah!" For the first time, I let out a scream of pure agony, pain ripping through my body as blood flowed from my orifices, but I kept focus.

'I'm sorry to every innocent I've ever killed. Before I truly learned to control myself, I was nothing but a hotheaded killing machine and I want to say, I'm sorry. None of you deserved to die back then and if my death now will help you all…then so…be it.' The world around me slowly faded to black as I felt myself sink deeper and deeper into the river before air flooded my lungs and I gasped.

"You actually did it! You goddamned genius demigod bastard! Hahaha! I never doubted you for one second!" I can't tell you how confused yet relived I was to hear Oceanus cheering next to me, my vision returning to see him giving me a wide grin as he knelt next to me.

"W-W…what…what happened?" I asked blearily as I slowly sat upright, Oceanus just grinning as he helped me up. I stumbled slightly as I stood back upright on shaky legs before my eyes widened at the third being in front of us. It was an elderly man with black tar-like hair and dark green eyes, dressed in a white toga and barefoot as he smiled at me.

"Theseus, the 16th Reincarnation of the Demigod Theseus and the Crown Prince of Olympus. Congratulations on passing the 4th Trial of Olympus." The man said with a smile, making me frown as Oceanus raised an eyebrow.

"Acheron? I thought you didn't like meeting with demigods." My eyes widened at the name as Acheron chuckled and landed softly on the ground.

"I would stay away, but I wanted to be here in person to congratulate the only successor of my trial."

"So, the river Acheron isn't the River of Pain, is it?" I asked and Acheron chuckled as he nodded.

"It is, but that is just one of the two names it has. The second name is the River of Forgiveness. The only way to pass this trial is to apologize for all the innocents lives you have slain and if the souls do decide to forgive you, then you'll be let free."

"…So, they all actually forgave me?" I asked in shock, to which Acheron smiled and nodded.

"I don't know why, but they all did. Either you have a lot of charisma or you're just the luckiest Theseus I've met. Now then, you are now allowed to continue to the final trial and I hope that you'll be the one who finishes the final trial. Until we meet again, young demigod." He declared with a smile and a nod, sinking back into the river as we just stared at them before I sighed.

"So, what now?" "I have no damn clue. All I know is the last river's the spot for your final trial, but we've never made it this far and so, all we have is just theories." Oceanus said with a shrug, to which I sighed before I nodded.

"Fine, then let's head to the final spot." Oceanus smiled as he nodded and stomped his spear on the ground, his teleportation crest appearing under us before we disappeared. As the light of the teleportation died down, I blinked a few times to get my vision back before I heard Oceanus speak.

"Welcome to the most sacred place in the entirety of the Underworld. Welcome to the river upon which all sacred vows are sworn. Welcome to the River Styx." He declared with a soft smile as we stared out into the river of dark water and pollution in front of us and despite all of that trash, I couldn't help but marvel at the dense aquatic aura flowing off of it as I took a deep breath.

"So, the same as always?" I asked, sighing as Oceanus just shook his head.

"No, the River Styx is endless and bottomless, filled with lost hopes and dreams as well as the wishes of humanity that never came true, which means that it is constantly growing every day. Even if you manage to even make it a fifth of the way down, by that time the river would have at least doubled or even tripled in size."

"Great to hear. So what do I actually do?" I asked, to which Oceanus just smiled as he took out a dark green orb from his toga and handed it to me.

"That is the Heart of the Sea, the crystallized souls of every aquatic and/ or sea-based species that have died out since the beginning of time. The only way for you to even survive this trial is to swim to the middle of the river and smash it into your chest. After that, who knows what else?"

"Okay, so swim to the middle of a river that is constantly growing and if I do get there, smash a glass orb into my chest. Did I get that right?"

"Yep! Good luck!" He said with a cheerful smile, ignoring my doubtful gaze as he gave me a pat on the back before walking away.

"Okay, Theo. Swim to the middle of a river that grows every second and them smash a glass orb into your chest to maybe restore your powers. Just like before." I gave myself a pep talk as I walked towards the shores. As the water washed over my feet and to my surprise, instead of a cold feeling, it felt as if my feet were dipped in a warm viscous liquid as the water stuck to my feet before sinking back into the river.

"Okay, so it's like swimming in warm slime. Oh gods, why do I feel like I'm going to hate this?" I grumbled before I took a deep breath, taking a few steps back before sprinting forward and diving into the river.

Swimming in warm slime, while a bit uncomfortable, was far better than swimming in chilling cold water and water that constantly burns your body.

In fact, dare I say, that after Phlegethon, this was probably my favourite river to dive in to.

It was just a lot more uncomfortable to swim in.

Swimming towards the middle as best as I can, I grumbled as it didn't feel as if I was getting closer, feeling as if I was swimming in place the entire time.

"Come on, Styx! I don't need much. Just let me get to the middle." I pleaded and to my shock, it felt as if the water gripped my body before a manly scream escaped my lips as I was ripped through the water, slimy water splashing against my face before I came to a stop in the middle of the river.

"T-Thank you, Styx." I said with a shaky smile and I heard a soft whistle echo through the air around me before it disappeared, replaced by the wails of the souls of the Underworld as I let out a soft sigh.

"Thank you, demigod luck." I muttered with a smile before I lifted up the Heart Orb, thanking my lucky stars that I managed to keep a grip on it and not drop it in the river.

"Just smash it and get it over it." I muttered to myself with a frown, taking a few deep breaths as I lifted the orb before grunting as I smashed it into my chest as hard as I could.

Did I expect it to shatter my ribcage and stab me with large shards of glass? Yes.

What I didn't expect was the orb to shatter completely and a dark green mist to envelop my body, the mist growing to a bright neon green light that blinded me as I grunted and swam back a few paces.

As I blinked to get my vision back, I looked around at the blurry world around me before my eyes widened as I saw the change in terrain.

Instead of floating in a river, I was deep underwater, standing on the bottom of probably an ocean as a beautiful ebony-haired woman floated in front of me, her obsidian black eyes staring directly into my own. Dressed in a purple and black dress that billowed around her like volcanic smoke, she stared at me with a stoic expression before she smiled.

"Child of Poseidon & Champion of Olympus, congratulations of completing the Five Trials of Oceanus."

"Wait, what? It's done." I asked in shock, to which Styx just smirked.

"Yes and no. Yes, you have finished the Five Trials of Oceanus that was granted to their namesake by the Lady Fates. If you wish to get your powers back as well as achieve Godhood, however, you have a final trial to undertake."

"So, you're telling me that the last five trials was for nothing."

"I would not say for nothing as the trials were used to cleanse you of your mortality and leave only your soul behind. Now, the final trial is to decide whether or not you are ready for Godhood." I stared at her before I sighed and nodded.

"Okay, then. I supposed I made it this far. What is the trial I have to do?" I asked, to which Styx just snapped her fingers and our surroundings changed.

We were now both standing in a colliseum arena, crowds of skeletal figures cheering in the crowds as I looked around before turning to see Styx sitting in a throne overlooking the arena.

"You have but one task, young Theseus. Defeat your opponent and you shall be allowed Godhood!" She declared loudly, the crowd cheering as the gate adjacent to me slowly opened.

"Uh, if you haven't noticed, no powers." I said, to which she just smirked.

"That sounds like a you problem, but do not worry. Your opponent is but a simple human as well." She said with a cryptic smile, making me grumble as I reached for my pocket and swiftly uncapped Anaklusmos.

As the gates fully opened, I got into a stance, ready for combat before my eyes widened as my opponent gave me a sadistic smirk.

"What? Did you think you were the only one wanting power?" A picture-perfect copy of me said with a smile, though his eyes were a complete black with green emerald circles for irises as a xiphos made of a dark silver appeared in his grasp.

"Stygian Iron." I muttered with a frown, the copy Theseus chuckling as he got into a perfect copy of my stance just a few feet away from me.

"The battle for the position of Godhood is about to commence. May the best fighter win. Let the battle…begin!" And Copy didn't need more incentive as he lunged forward, making me grunt as I parried his powerful downwards strike to the side before slipping into his guard.

Copy grunted as an elbow slammed into his sternum before I frowned as he gripped my elbow and brought his own down onto my back, forcing me to kneel with the strike to minimize the damage before I rolled to the side as he barely missed breaking my arm.

Flipping to my feet, we both stabbed at the other and leaned to the opposite side, the blade sailing past our heads before we both gasped as we landed a double gut punch at the same time, forcing us to stumble back as I frowned at my foe, who just grinned back.

'He's a perfect copy, down to my fighting style.' I thought to myself with a frown as I slowly twirled Anaklusmos in my grip, not missing him doing the exact same with a sly smirk before we both leapt forward.

Sparks flew as our xiphe clashed against each other, both of us swinging and moving as best as our forms allowed us to as we both tried to deliver a fatal blow to the other.

A thrust from me was parried to the side and countered by a horizontal slash, only for me to dodge that slash by rolling with the parry and coming to a standstil behind him.

Swinging Anaklusmos at his neck, I grumbled as he ducked under it before dropping and swinging a leg sweep behind him, forcing me to jump back as he spun back to his feet while grinning at me.

An idea came to mind as we stared at each other before I lunged forward, Anaklusmos transforming in my grip before I stabbed its trident blades forward. Copy ducked under my attack and rolled to the side as I brought it down, gripping his xiphos tightly before he swung at my neck.

I grinned at his attack before I let go of my trident, his eyes widening as I leaned into the attack before ducking at the last second, catching Anaklusmos in my off-hand before Copy gasped as the triple blades stabbed through his left leg.

He stumbled slightly to get his balance back, but that was all I needed as Anaklusmos transformed back into a xiphos, slicing off his dominant hand that was carrying the copy Anaklusmos before I grunted as I caught his blade midair and swung both blades at his neck.

"Ah…well…w-well…d-d-done…my copy…" He wheezed out with a bloody smirk as blood flowed freely from the gaping hole in his throat before he fell backward.

"Damn, I'm glad that worked." I muttered with a frown as I stared at the still corpse of my copy before looking up as the world around us changed again, my eyes narrowing as I realised that we were now floating just a few centimeters above the River Styx.

"Was that the final trial?" I asked and Styx smiled softly as she nodded.

"It was and I must say, I've never seen a demigod of Poseidon that focuses on using strategy more than using his father's domains. Well done." She said with a smile, making me groan as I fell onto my backside, floating in the air as Styx spoke.

"Now, we just have to do a few more things."

"Oh, come on!" I groaned, to which she giggled as she shook her head.

"Do not worry for there are no further trials. These are just things we need to do to finalize your ascension to Godhood."

"…Fine. Hit me with them." I grumbled as I stood back up, Styx nodding before I raised an eyebrow as her eyes transformed into bright green orbs.

"Theodore Richards, reincarnation and inheritor of the soul of the demigod son of Poseidon, Theseus, & Crown Prince of Atlantis. Present your sacred weapon." Her voice was a lot more deeper than before, making me sigh before I looked down at the blades in my grasp. Anaklusmos would be enough, but if it was going to be the weapon of a God, it needed to be stronger.

"Both Anaklusmos and its copy. Fuse them into one." I declared with a determined frown as I turned both blades in my grasp and presented the hilts to her, Styx nodding as the blades floated out of my grasp to a standstill in front of her. A bright seagreen glow covered the blades before I frowned as I was covered in the same glow, Styx staring at me before she spoke.

"To ascend to Godhood, envision the one thing that keeps you attached to the Mortal World."

"…As in an earthly attachment that keeps me going day by day?" I asked, frowning as Styx didn't answer and just stared at me.

"I guess, my mother was there for me whenever I needed her and I do feel a big attachment to her, but then, there's also aunt Amphitrite that didn't have to let my mother and I live with her family and yet, she did. If I do include them, then I have to include Triton for being the older brother that I didn't think I need. Then there is the ladies and Kunou to consider as they brought me out of the dark business of the Organization and help me rediscover what true happiness is."

"And yet, you know they are not the attachments you needed. Declare your earthly attachment that will keep you to the Mortal World."

"I guess then, there's only one person that I should truly be thankful for. Despite his frostiness the first time I met him, he didn't have to raise me and yet he did, making sure that my life was the best I could have as well as asking his own family to help raise me and they did without asking for anything. Hah, I guess what I'm trying to say is that I'm thankful to my Father for everything he did for me over the years. He's the being that keeps me attached to this world and to be honest, I couldn't have asked for a better father." I declared with a broad smile, a few tears in Styx' eyes as she smiled and nodded.

"Then with that decree, young Theseus, arise from the Five Rivers of Hades and be reborn…as a God." And with that a bright emerald glow enveloped the entirety of the world around me as I felt a sense of peace and calm wash over me and smiled as I closed my eyes.

The last thing I heard was a familiar voice saying something before I felt my consciousness slip and I blacked out.

A/N: And…there…we…go! The birth of a new God!

Next chapter, training continues along with a check-in with Yasaka and Rossweisse before we return to Kuoh for more battles.

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

Ba-Bye~!