This is an alternative ending to the chapter black saga. Somehow, someway our heros defeated Sensui in 4 on 1 combat before the tunnel opened to demon world. Yusuke didn't become a demon.
"Stupid, damn nature hike," Yusuke said as he struggled to reach the top of the stairs, "couldn't have done this at Kurama's house or mine or something?"
"Stop complaining so much," Keiko replied, "we're already late. Hi everyone!"
Kuwabara shouted, "We already started without you."
"We have not," Kurama added.
"I'm glad you two could make it," Yukina said, smiling.
The couple walked over to Genkai's living room. As he entered the temple Yusuke said, "About damn time we got a break and celebrated our victory with aborted world ending schemes. Where's Hiei?" He looked around the room and saw Kurama, Kuwabara, Shizuru, Yukina, and Genkai. "Where's Botan?"
Kuwabara replied, "You know shorty's never going to come but I haven't seen Botan in a while."
Yusuke and Keiko sat in the circle everyone was in Botan flew down from her ore and ran into the room. "I'm sorry for being late!" she shouted.
"See Keiko," Yusuke said, "we weren't the only ones."
Shizuru replied, "Come on kid, there's still plenty of beer!"
"No time for that!" Botan said, "Sorry to interupt the party but Koenma has another case."
"WHAT THE HELL!" Yusuke shouted.
Kuwabara replied, "Already?"
Botan sat down and said, "Listen to me. It's not like the worlds hang in the balance or anything. In fact, it'll sound similar to a case we've done in the past. A rich crimelord named Akiya has gotten together with some demons and even taken one hostage deep within the mountains."
Yusuke asked, "Can't any of these rich crazy evil people live in a city nearby or something?"
"Shut up and let her talk!" Genkai insisted.
"An ice maiden is being held captive and they're taking her tears by force," Botan explained.
Kuwabara asked, "An ice maiden, like Yukina?" He looked at her.
"Her name is Rui," she continued.
"Rui?" Yukina asked, "You're sure?"
Kuwabara asked, "Do you know her?"
Yukina nodded and explained, "She was the woman that raised me after my mother died, and she's the one that told me I have an older brother." Botan fell over at that comment while Yusuke and Kurama stared at her.
Yusuke asked, "Let me guess, we're going to have to walk miles into a fortified complex of demons in order to rescue her? If we meet another Toguro after this I'm done."
"Actually," she continued, "we scanned the ground. They're covered in explosives. We'll be flying you in a large helicopter instead. It'll be less dangerous that way."
"Alright!" Yusuke shouted.
Kuwabara replied, "Just like old times."
"I'd like to go too," Yukina said.
"Really baby!" Kuwabara said, grabbing her hands, "Want to see the great Kazuma Kuwabara in action?"
She explained, "Actually, I want to save Rui. I wonder why she left the ice world." Kuwabara fell over in shock.
Yusuke looked at Kurama nervously. Kurama said, "I don't see the harm in that. I believe Hiei should go with us too-since we're fighting demons." Yusuke nodded.
"Forget runtboy," Kuwabara replied, "we have all the power we need. I got a new shiney sword, remember?"
Botan replied, "Do you know where Hiei is, Kurama? If not I can try the whistle again!"
"No!" Kurama answered, "Not that. I figured we'd need to do something like this again. Do you still have that demon compass?"
"Of course."
"Here," he replied. He pulled a black hair from out of his pocket.
"Is that-" Kuwabara started to ask.
"Hiei's hair?" Yusuke finished.
Kurama explained, "I plucked one out of his head when he wasn't looking the last time I saw him in case something like this ever happened. The last time I saw him he was waking up from our fight with Sensui and cut up chapter black."
"After all of that he just broke it?" Yusuke asked.
Botan said, "This is perfect!" She grabbed the hair and took out her compass. She curled up the hair and put into the compass before closing it. "He's only 1/2 a mile away, to the east of here."
Kurama said, "I'll go alone and try to convince him." He took the compass from Botan.
"Come on," Kuwabara said, "we don't need him." Kurama left without acknowledging him.
Hiei stayed in the tree as he started waking up from his nap. "Hiei," he heard his name from out of nowhere.
"Kurama?" he asked, nearly jumping out of his skin and falling out of the tree, "Where the hell did you come from, and how did you find me?" He looked down at the redhead who looked innocent.
"Yusuke got a new case-" he started.
"You can stop right there," Hiei replied, "no matter what you say I'm not going to be dragged into it."
Kurama said, "Alright, I'll tell Yukina you said that."
Hiei glared at the fox and asked, "What does she have to do with this?"
"If you let me finish I'll tell you."
"Say it!"
"An ice apparition is being held against her will," Kurama explained, "and apparently Yukina knows her. Her name is Rui."
Hiei stiffened at the sound of that name. "Rui?" he asked coldly.
He continued, "Apparently after your mother died this woman named Rui raised her. Yukina wants to rescue her with us. I thought you might want to come along to make sure she stays safe."
Rui, he thought, the woman who left me for dead. Hiei leaned back to the tree and said, "That woman doesn't deserve to be rescued. She caused our mother great grief and pains." He couldn't bring himself to tell Kurama the full story as he remembered being dropped from that cliff so many years ago and hearing his mother's cries.
"Yukina must not know," Kurama replied, "she's insistant on coming with us to help her. Perhaps if she knew the truth-"
"Nonsense," Hiei said, coming out of the tree, "I'll make sure that doesn't happen."