With Kai's unsealed state, he quickly began matching the Blind Swordsman without having to rely on his left eye's automatic combat mode. His wings were used for both speed and attacks. That meant the Blind Swordsman had to block seven attacks at supersonic speed.

Kai no longer had to use his artificial arm and leg to forcefully block him and risk damaging them. But, even though Kai increased his strength, his opponent was still growing. With each second that passed, his seal slowly began lifting and soon, he would be able to overtake Kai.

It was the same deal with Fate, but unlike that person who believed that everything would go his way—today's opponent wasn't an idiot. The Blind Swordsman wasn't immortal like Fate and he could be killed using mana, but that would only serve to send him back to Howard. Once he dies, he wouldn't be able to return in the short-term but he eventually will, and when that time comes, Kai would no longer be his match.

S-class was the peak of humanity's power in contemporary times but it was nowhere near enough in the war. There were angels and demons who could swat S-class humans like they were flies. The four generals of the fallen hero were even stronger. That's why he had to gain their cooperation before then.

While they were fighting, a translucent barrier was erected to surround the arena and there were several dozens of people who were supplying it with power. Erina and the others were included. By cooperating with Aubrey Academy, they managed to create a joint barrier enough to withstand the stray attacks from Kai and the Blind Swordsman's battle.

"I don't think you're the type of person to rush into a battle without making the right preparations, what have you got up your sleeve?"

The Blind Swordsman commented whilst the onslaught of attacks.

"If I had one—urk—then why would I tell you?!"

A blow had gotten past Kai's defense and struck him. Kai moved his wings to block the next attack and created a massive gust of wind to push the Blind Swordsman back. But, forget him being pushed back, he didn't even flinch. All it served was to create distance between the two of them that could be covered in an instant by either of them.

Kai stretched his neck and joints and flapped his wings a few times before looking at the Blind Swordsman.

"What do you say we take it up a notch?"

The Blind Swordsman raised a brow and loosened his grip on his sheathed katana.

"You're saying that this isn't your limit? I can hear your bones and flesh breaking apart and regenerating by the second."

In response, Kai laughed.

"This level of pain isn't enough to wear me out. But, you're right. This is my body's limit. Any more and I might just explode. However, that's just my body, I still have mana, don't I?"

Lightning began crackling around Kai and took out a saber.

"I'm going to pay you back for hurting Yoko."

Kai didn't wait for a reply and vanished with a flash of light and a thunderclap. He clashed with the Blind Swordsman and for the first time, knocked him back by a few meters before retreating back to his previous spot.

"...Such speed. Even so, can you really control it?"

Yoko's innate ability,『Celerity』 had unlimited potential but the speed Yoko could display was nowhere near the level of lightning. Even Kai couldn't control lightning on his own, it was only natural for the Blind Swordsman to doubt him.

"No," Kai spoke without a hint of hurry or alarm, "I can't control it in normal circumstances. If you were unsealed, matching this speed would be child's play so who's to say that it's going to always be impossible for me?"

The Blind Swordsman snorted, "even when I was unsealed, it took me decades to master lightning speed. And, my sealed state, where did you hear of it?"

Kai shrugged his shoulders.

"It was just a guess, most of the strong ones seem to be always sealed after all. Now, enough about that, why don't we continue?"

Kai didn't take a stance, he just suddenly turned into a streak of lightning and attacked the Blind Swordsman from the front. Then, he moved to the side and charged again before repeating the same movements. He attacked the Blind Swordsman in four directions and was blocked each time.

Looks like I have to go even faster...

Kai moved away, stopped, then charged towards the Blind Swordsman. Instead of four directions, he attacked from eight, then twelve, then sixteen. He continued to attack at lightning speed but each time he went faster, his body began breaking apart at a faster rate and soon, his vampiric regeneration wasn't enough to keep up.

If Kai were in slow motion, then everyone would be able to see his skin breaking apart, hear his bones creaking, and be shocked by the amount of blood he had already lost and is still losing. His whole body was covered in steam and he looked more like a machine than a human at this point.

The only two people who knew about his current state were Kai and the Blind Swordsman. Erina and the others were oblivious to his pain. All they saw were flashes of light and because of the consecutive thunderclaps, they couldn't hear anything.

The battle seemed like it lasted long but the truth was that it hadn't even been ten or so minutes yet one side was already beginning to break down.

Kai clenched his teeth and flapped his wings to dodge an attack before retreating a distance away. His body began healing while steam rose up from his body.

The Blind Swordsman sheathed his katana again.

"It took me a bit of time to get used to your speed. You aren't able to control it on your own but with six wings, you're able to change the direction by flapping them on one side. What absurd muscles."

How many flaps did his wings do while he was at lightning speed? How was it even possible?

But, it was the absolute limit of Kai's body. Other than with Reo's enhancement, there was no other way he could increase his body's base power.

Kai released his magic power and pointed his arm in the direction of the academy.

"Hm?"

"Everyone, release the barrier for a few seconds."

Kai used Telepathy and contacted all of the members of Memento Mori. They knew better than to question his judgment, especially in a situation like this and informed the academy's S-class.

The instant they released the barrier, flying blades flew over to Kai and began covering up his body starting from the right arm that he had held out. His left arm and leg weren't included because there was no way that the living metal could be a match for them. He had promised the chairman about leaving behind a single piece of the living metal at the academy for research purposes but because he didn't have any immediate use for them, he left them all.

The blades flew from the academy and broke through whatever container they were held in to get here. The chairman must be in quite the panic.

"Such a large quantity of living metal. It's impossible for someone as young as you to acquire that. Even in the past, false immortals that scoured the worlds in search of something that would help them become true immortals never found that much.

"That confirms it, you, who reek of the power of time, are from the future and are using your knowledge in the past. The same as my lord."

It was the only possible explanation for all the mysterious things that had happened. When they first encountered each other in the training field, Kai was prepared for his attack and didn't look surprised at all. The second time they met was here in the Tournament of Swords. Their previous meeting should've been just a passing event that the two of them would forget soon enough but he had entered with the same people that he was with on that day and they intentionally provoked him as well.

That meant this person was from a future where the generals had descended on Gaia and carried on his hate from the future into the past. There were too many factors that one person could influence if they had knowledge of the future just as Howard had changed the past to become who he is today.

"That saves me from explaining myself. I know who you all are and I know when you'll descend. I also know that you guys have yet to regain your full strength and that even if I kill you here and now, you'll go back to the fallen hero's side."

The Blind Swordsman raised a brow, "I don't understand. Since you know that much, why are you interfering with me?"

"It may not have happened before, but I'm sure that you were sent here because you came to kill me. You, the Angels, Demons, Gods, Devils, all of you know about the prophecy, why shouldn't I? That fallen hero's eyes are special and I knew that the moment I returned the past, he was made aware of my existence."

Kai's wounds were already healed. A vampire's regeneration was even greater than Greater Self-Healing. Although Kai's wounds definitely would have landed him in critical care, it didn't even take half a minute for him to be in perfect shape. However, his breathing was still rough. He had an unlimited supply of mana and he could heal all of his body's wounds no matter how severe but his stamina wasn't something he could recover.

Moving at the speed of lightning was taxing on both his mind and body.

"If you know that much, then you should also know that it's futile to oppose my lord. Or, do you mean to say that you were someone who was able to threaten him in the future where you came from?"

Kai shook his head and stepped forward.

"No, I was nowhere near that level at all. But, that doesn't mean I can't. Nobody can tell me about my limits, I decide them for myself. I don't care if that fallen hero has a power rivaling both the King of Gods and the Demon King, he will bow before me soon enough."

The Blind Swordsman was about to attack in anger but all of a sudden, pressure began to weigh down on his shoulders. No, it wasn't just him. The entire area, the city, and the world began shaking under that pressure.

"This presence... a God!"

Kai completely released Soul Aura and the soul of a former God. Although neither of the two would be able to boost his skills, it would close the gap between Kai and the Blind Swordsman's power by making it so that the latter would have to constantly fight against the pressure.

"Let's begin the final phase of my plan."