Yumeji couldn't hold back her screams of agony as Konomi had slammed down her right hand-blade upon her right shoulder. Just as Yumeji tried to strike her down with electricity, Konomi was already behind her and struck her back with her left hand-blade.

"Too weak. My attacks are too weak. Compared to Tomioka-senpai, even when i'm copying him using my Beast Power, I can't even bring out half the strength he does."

"Get away from me, you damn brat!!!!!'

As Yumeji screamed out, she used her telekinesis to grab Konomi by her throat and hurled her through a tree. Soon Yumeji's body began to change. Right now, she had no room for holding back. In this moment, Yumeji needed to destroy Konomi at all costs.

"Beast Power, Monkey!"

Suddenly Konomi jumped into the air as she kneed Yumeji in the face. However, Yumeji didn't flinch as she grabbed Konomi and threw her to the ground. Seeing this, Yumeji simply laughed at the young chief's display at this moment.

"Your normal power isn't going to cut it anymore. You're still too inexperienced, little girl!!!!"

"You're right....my normal power isn't enough. It's a good thing you threw me to my solution for that problem."

As Konomi said this, she smiled as she was holding onto a chain. Suddenly the girl leaped into the air as she landed on Yuuki's back. Soon a bright pillar of light appeared as Yuuki's form began to change. The moment the light simmered down, Yumeji saw Konomi standing before her in armor.

"With this ....maybe i'll finally catch up to Senpai."

~Outside the barrier~
"We can't keep up!"

That was the thought of both Kojima brothers as they felt their faces being grabbed and slammed into the ground. Suddenly Nagisa, turned around and grabbed Medusa by her wrist as slammed his right fist into her face and smashed her through a tree. Just as Medusa was sent flying, Nagisa was already in front of her as he slammed his fist into her face again as her body crashed into the ground.

Suddenly the boy spun his body and kicked Hiroaki in the chest as the man crashed through a tree. Next, he slammed his elbow behind him as Shigeaki nearly vomited as his gut got elbowed and he was struggling to breathe. However, he didn't have time to catch his breath as Nagisa slammed his knee into the man's face.

"Vector Arrow ×3!!!"

"Water Breathing, Eleventh Form....."

The moment Medusa launched her Vector Arrows, she could only look in shock as they were instantly cut to ribbons as Nagisa's right hand-blade was now in front of him. However, right now, Nagisa was completely focused. His heart was beating so fast, he could hear it ring in his ears. His body felt so hot, it was like he was being engulfed in flames. But more than that, right now, he had only one desire fueling him at the moment. That feeling........

"I will kill you, Medusa!"

.......was Murderous Intent.

~Meanwhile~
"So, did you tell him about the side effect of the mark, Bang? I am positive he will reawaken it."

As he placed the former members of Yamazaki under his custody, Gun was currently speaking to Bang about Nagisa. He knew during the fight with the Kojima brothers and the other traitors of the Yamazaki that Nagisa was close to reawakening the mark again.

"To reawaken the mark...Nagisa has struggled to do so. The first time he awakened it, he saw a part of his past right in front of him. His anger reaching its peak, his body feeling hot as his heartbeat was uncontrollable. That was the reaction brought when he first saw Shikoku. Tell me, why wouldn't he have the same reaction after being trained by Goo and I?"

"Because he had no reason to be angry or scared of someone weaker than him. He was confident he could kill her because he faced two people far more frightening than her."

"Correct. However, his fight in Yokohama is what brought him back to the path of unlocking the mark again. The first being the emotional trigger. Because the very source of what caused his life to spiral was right in front of him. It makes sense for Medusa to be the full target of his hatred, even more so when he was positive she was dead. Now the next condition was to get him near death again and to force his heartbeat and body heat to be pushed to the limit."

"The clone of Daniel Park. It forced him to use Ultra Instinct himself. That was probably the most Nagisa has struggled. But that was just the near death portion. To have your heart beating uncontrollably fast, your body temperature to be at least thirty-nine degrees Celsius (102° F). The thing that caused that condition to be met was......Fist of Exploding Heart Liberation."

"Now to answer your question. He does not know of the side effect. That most who achieve this mark would die at the age of 25. However, Tomioka Nagisa will not fall to that curse for two reasons. The first being the God of Thunder, Kuusetsu. Her essence was injected into the boy's body and caused some minor changes. The speed at which his body regenerates wounds such as cuts and the like have been enhanced, not only that, it seems to have made his five senses even more heightened and his vitality has increase immensely."

"The second condition must be......Azuma Tobera."

"Her peach ability, Trancience, absorbs the life force of living things. She has two applications of it. Either to store all the excess life within her or to give it to others which causes them to heal and such. Now tell, what would happen if she gave that excess life force to Nagisa, especially now that his body is slightly being strengthened by the God of Thunder."

His body would adapt to the strain. Through Tobera's healing and Kuusetsu leaving her essence inside of his body, Tomioka Nagisa can use the Demon Slayer Mark without the reprucesuions taking his life. While he'll still feel exhaustion and need the rest, his body won't destroy itself to the point his life is cut short. However, one thought came to Gun Park.

"As amazing as that is, there is one weakness Nagisa has that the enemy can exploit. That weakness......."

~With Nagisa~
"I'll kill her!"

"Water Breathing, Tenth Form: Constant Flux!"

As Medusa was launching several arrows at the boy, Nagisa charged towards the woman while performing a continuous flowing attack with his right hand-blade as he cut down the arrows and got closer to Medusa. The attack grew even stronger and faster over time through the momentum. While Nagisa was getting closer, Medusa was seen holding onto something in her right hand.

"I'll die. I knew that this body wouldn't last when I came up with this idea. That's why, the body Medusa Gorgon will conduct her final experiment. This will be to test the full potential of our enemy......and to destroy the Corps completely."

"Water Breathing, Seventh Form:Drop Ripple Thrust!!!"

Just as he was in front of Medusa, Nagisa performed a precise and quick thrust of his right hand-blade. However, instead of dodging it or using her arrows to block it, Medusa let Nagisa stab her inside of the heart. As the woman coughed up blood, she smiled as she stabbed a syringe into Nagisa's left hip.

"This is the last time you'll see me in this body. Before we meet again, be a good little boy and help me do one last experiment with this body. Rampage to your heart's content, human debris."

As Medusa said this, her shuuki like body began to crumble into dust. Nagisa didn't say a word. As the mark was still upon his face, something suddenly snapped as his body felt even hotter than before. It felt like he would lose consciousness at any second yet his body refused to let him rest. This was just proof that it was a success. The true purpose behind Medusa wanting to confront Nagisa. It was to use that drug and to force out this side of him.

~With Kyouka and Riu~
"How are you holding up, Kyouka?!"

"Everything is fine on my end, Riu-san. Lending is in action, so Konomi and Yuuki must've unlocked a new slave form. Hopefully it's enou-"

As Kyouka and Riu were trying to eradicate any shuuki left outside of the barrier that Yumeji made, they noticed something unusual happening. Birds, squirrels, any nearby animal was fleeing the area. Not only that, the shuuki that were fighting them did something out of the ordinary. The beasts began to kill each other with a fearful expression on their faces.

"The shuuki are killing themselves?"

"The animals in this area are also fleeing. Usually when this happens, that means a predator is nearby. But there shouldn't be an animal like that in this ar-"

Before Riu could finish her sentence, her eyes widen in horror with what she saw next. Right before her and Kyouka stood Nagisa. However, something was not right. Right now, he didn't say a word and his aura wasn't the same as before. Instead of the stillness of calm waters, his aura felt like a raging tsunami ready to consume everything in its path. The moment Riu looked at his eyes, she quickly glanced at Kyouka.

"Kyouka, call the rest of the corps. Tell them to bring as many chiefs to our location as possible, quickly. Get Azuma Tobera and even Bang to show up if possible."

"Why? Is Yumeji really that big of threat?!"

"No, Kyouka. The biggest threat to all of us right now......"

Suddenly, both Riu and her husband that she brought back from the dead had their heads grabbed by Nagisa and slammed into the ground. Shortly afterwards, Riu felt her stomach being stomped by Nagisa as she was now rendered unconscious. The moment he turned around, Kyouka noticed two things about Nagisa. The mark that was on his face and the way his eyes changed.

[Demon Slayer Mark x Ultra Instinct]

"My hands......they're shaking. Can I even fi-, no.......can I survive long enough to even call for help?"

The Demon Slayer Mark appeared on his face once more. However, Gun Park's prediction came true. While Nagisa awakened the mark again, Medusa exploited his one weakness in an attempt to destroy the Corps. Nagisa's weakness........was his lack of control over Ultra Instinct.