Puu lands, bringing Koenma and, to everyone's shock, a bruised, shirtless, battered but very alive Yusuke Urameshi, who marches straight to his teammates to reproach them: "If you thought I'd throw in the towel and leave this fight for you, you got it all wrong, pals!"

Kuwabara can't believe his eyes. He had checked Urameshi's pulse in the Irima cave and his heartbeat had stopped. "Oh yeah... my heart isn't beating now either," Yusuke comments as if it were just a curious little detail.

Hiei and Youko Kurama let out a wild chortle. "Don't worry, Yusuke," says Kurama. "There's a core doing your heart's work now."

"The demonic core," explains Koenma. "There's youkai blood running through his veins." Hiei enjoys the irony of the Reikai Tantei becoming a demon. Yusuke says he feels nothing different though.

He's eager to resume the fight with Sensui, but now Hiei, Kurama and Kuwabara found a new strength with their friend's return. As they flame on their ki and argue on who is going to fight now, Sensui observes them and realizes that Koenma really recruited the best this time.

Yusuke says he understands his teammates' feelings, but asks them to let him take care of Sensui. "Please. Leave that to me." The three agree.

In the Irima cave, the Tokubetsu Boueitai nervously question Commander Otake: if they are the strongest soldiers in Reikai, how could they be so helpless in detaining Urameshi? Otake tells them about the S-class demons, a class these soldiers didn't know about. Yusuke's ancestor was/is an S-class youkai; Sensui is human, but his powers are just as great.

The soldiers don't react well to the news, but Otake orders them to concentrate on the task at hand: "If the law in Makai says to attack, ours is to protect. That's why Reikai created that barrier to keep the A and S classed demons to come here. In 48 hours this tunnel has to be sealed! I want all of you working on it non-stop!"

In Makai, the fight starts. The clash of powers creates big bursts of light and devastates the landscape around them. Yusuke points his index finger and a Reigan soars towards Sensui, who barely dodges. It brushes and damages the former Tantei's armor, and utterly destroys a mountain a few miles away.

Yusuke is more surprised than anyone with the potency of the shot. Hiei, with trembling eyelids - the Kokuryuuha aftereffects? -, comments that Yusuke is intelligent and soon will learn to control his new power. Kuwabara reprehends Urameshi for wasting ki. Yusuke agrees: "I only have one shot left, so I'll keep it for later."

Sensui's aura flame on as he loses his armor to create another, more practical to attack. Yusuke is glad with the change.

Flying over Mushiori City, Botan sees Shizuru and Keiko in a bus stop and lands to ask them why they're there. Keiko tells her that Puu turned into a giant bird and flew off. "Puu did that? But if Yusuke is dead..." Botan trails off and apologizes for the clumsy slip. Keiko falls on her knees, crying, and Shizuru tries to comfort her. The ferrygirl suggests that they should look for Genkai.

Yusuke asks Puu to take his friends up to the sky where they'll be safe. The blue phoenix complies; only the Youko prefers to use that same butterfly-plant to glide on his own.

Sensui hits Yusuke twice, damaging more the landscape than the boy. The seven personalities clash inside his mind: fight on, stop, kill everyone, love the humankind... But Yusuke counterattacks and distracts him from the inner conflict.

The A-class demons in that living tower that tried to reach the tunnel to Ningenkai come back to attack them both. Sensui is annoyed at the interference and slay them all very quickly.

"Ningenkai or Makai, I don't care," says Yusuke. "Let's fight."

Sensui laughs. "I admire your simplicity, kid." He charges with everything he has, socking Yusuke mercilessly. The plateau where they were standing is disintegrated in seconds. Yusuke licks his lips, contented, and suggests that they should move to an open area. "You're seeing that mountain over there? It's in a wasteland."

"You sound as if you've been here before," Sensui points out.

"Maybe. Maybe my ancestors have."

Puu and Kurama follow the two to the mountain. "Puu and Yusuke are synchronized," Koenma comments. "They developed at the same time." Kuwabara says he didn't notice anything different in Urameshi. "Yet," Koenma amends.

Yusuke feels something strange. But focused on the combat, he decides to worry about it later.

He and Sensui take less than five seconds to demolish the mountain. A tornado of ki forms around the two fighters as they exchange quicker-than-the-eye punches. Sensui manages to hit Yusuke, who disappear in a sand cloud. "Show yourself, I know you're behind me," says Sensui. "There's no point in moving under the sand if you can't mask your youki."

Yusuke comes out, chuckling. "Got me! I can't control my ki. It feels like a wild stallion." Sensui smirks mysteriously, annoying Yusuke by not telling him what he's thinking about.

Kuwabara asks Hiei what he thinks of the powers of the two fighters. "Hn," Hiei replies. Kurama is sure that until Yusuke manages to control his youki, Sensui will have the advantage. Koenma thinks Sensui looks different now. They all agree that the former Tantei seems satisfied in meeting and adversary of his level.

Again Yusuke feels something, this time stronger. A voice in his mind tells him, "I'll teach you how to use your youki."

A cyclone surrounds his body. His hair grows long and wild, strange blue marks appear in his face, chest, arms and shoulders. His youkai nature has fully awakened now.