Kai turned around with the jade blade in his hand. His lips turned up in a grin, but the smile never reached his empty red eyes. The sinister smirk sent shivers down Jay's back. The ninja of lightning stared into his friend's cold expression, wishing he could disappear like Shade. 

"YOU STARTED THE WHOLE THING," the red ninja growled in a voice that wasn't his own. It sounded hollow and raspy. He pointed the blade at his target, ready to strike. 

Jay backed up a pace. "K-Kai... This isn't you!"

Kai laughed with no sign of humor and drove the blade closer to Jay's rapidly beating heart. 

"Oh, but it is. I'm just a bit..." He dug his weapon into Jay's chest, causing the blue ninja to stumble backwards with a cry of anguish. 

"...different."

10 minutes earlier...

"Hey Kai, I heard that Master Chen is going to call a meeting in a few minutes. You want to get to the arena early with us?"

Cole and Jay stood outside their friend's door, shuffling their feet on the ground as they waited for their friend to answer. 

Jay sniffed, "Are you sure he's even in there? It's not as if he wants to stay in his room all day."

Cole cocked an eyebrow. "Well, do you have a better plan?"

The auburn-haired ninja shrugged, looking at the floor. "...No."

"I didn't think so. Let's wait a few more minutes. If he doesn't answer by then, we'll go without him. He can figure out there's a meeting along with the others."

The pair of ninja waited a few more minutes, knocking on the door once more, before walking to the arena. 

"Hey by the way, where's Sensei Garmadon?" Jay asked, tilting his head to one side. "I haven't seen him since yesterday."

Cole shrugged. "I haven't seen him either. He's probably trying to find something to sleep on. I heard that he has been having to sleep on the ground."

Jay scowled. "I can't believe those jerks had the nerve to refuse to give him a room!"

"Yeah well, he wasn't even supposed to be coming to the island anywa—"

"I know," Jay interrupted. "But it's still really unfair! They could have given him Lloyd's room..."

At the mention of Lloyd's name, they both grew somber. The green ninja had been defeated by Skylor, who had stolen his power. Lloyd Garmadon had been caught unaware and defeated.

Cole punched his fist into his other hand. "But they won't defeat US that easily," he growled.

Jay nodded eagerly, and they turned their attention back to finding their way to the arena.

Meanwhile, Kai was brooding in his room. He had heard his friends knocking on his door, but he was too upset to talk to them. 

He closed his hands into fists and drove them into his mattress with an angry yowl, in an attempt to get rid of all his bottled up anger.

He kicked his nearby trash can as hard as he could. It smacked into the wall with a satisfying clang. The red ninja turned from the wall and surveyed the wreckage before him. He had been kicking things around all morning.

Kai turned to the mirror on the wall, ready to smash it to bits. He pulled back his arm to give it a stinging blow, but suddenly...

He frowned and looked closer into the mirror, slowly putting his arm down. He squinted at his reflection before noticing that his eyes had turned a bloody red color.

The master of fire's mouth dropped open. What... What's happening to me? he thought angrily. Why does everything have to change?

He let out a low growl and smashed the mirror. Glass splinters flew around the room. One of the pieces dug itself deep into Kai's cheek, but he didn't notice. He was already spinning into a fiery orange tornado.

The small whirlwind spun around the room, flinging furniture and wreckage everywhere. The red ninja was in frenzy mode, and there was no way to stop it.

Finally, he slowed down and landed in a panting heap on the battered floor. As he gasped for breath, he finally noticed the blood streaming down his face. Kai took in a shuddering breath and rose from the ground. 

"Y-you'll.... pay.. for this..." he wheezed before falling to the floor and passing out.  

Jay and Cole had finally made it to the arena, and they were staring at the board that had the names of the fighters on them. 

Jay turned around slowly, noticing Master Chen sitting in the throne behind them. 

"You.. You want me to do... WHAT?!" he seethed, pointing a finger at Chen.

"Ohhhh, I just want you to fight Kai! That's all." He grinned, assuming innocence. "It's not much really."

Jay crossed his arms and humphed. "Well I don't want to!"

The noodle man smiled cheekily. "I don't think you have a choice, Master of Lightning."

Cole joined in. "But you can't do that! It's-it's..."

"Not fair?" Chen beamed. "Is that what you were going to say? WELL, TOO BAD! It's my game and my rules!"

"B-but," Jay stammered angrily. "I can't fight KAI! He's my friend!"

"Not to mention he's too hothea—," Cole muttered under his breath until Jay kicked him. "—OW!" 

"I'm not changing it," Master Chen harrumphed before turning his throne around.

The two ninja looked at each other in question before running back to Kai's room.

Chen's voice boomed through the giant speakers, "Oh, and by the way, THE FIGHT STARTS NOW!"

Jay yelped and started to run faster, only to run smack into...

KAI. 

The blue ninja's heart skipped a beat as the breath was driven out of him. "K-Kai!"

The fire ninja looked terrible. His tournament clothes were torn, his eyes were hollow and burning with red, he had a chunk of glass stuck in his cheek, there was blood running down his face and chest, his hair was matted with sweat, and even his skin was a pale grey color. 

Jay and Cole sucked in their breaths at the sight, leaving them both speechless.

Kai's evil red eyes turned to the two ninja. His sides were heaving and shuddering as he struggled to breathe.

"You....." he whispered in a frightening moan. "You s-ssstole everything from meee." 

Cole's eyes widened in fear. "Kai, what happened? We didn't steal anything from you!"

"Y-yeah, of c-course not," Jay stammered, shivering in horror.

Master Chen had appeared behind them. 

"Oh, did I forget to tell you?" he chuckled. "You'll be fighting Kai's dark side. Much different than the real Kai. I had Clouse add some minor glitches, but he was already almost there. You know, what with learning about his parents, falling in love with a spy, and whatnot. And lucky for us, he was still brooding about not becoming the green ninja. So the rest was easy! Have fun in your fight, boys!" 

The black and blue ninja gawked up at the dark side of their friend, not knowing what to do. 

Suddenly a thought came to Cole. "Jay, hurry up and find the jade blade! If you get it, you may not have to fight him, and Kai might turn back to his normal self!"

Jay still looked frozen, so Cole gave him a push. "GO!"

Suddenly the blue ninja burst into action. He dove over Kai's head and started smacking over the obstacles that had somehow appeared. 

"WHERE... IS... THAT... JADE BLADE?!" he yelped as Kai started after him. 

Cole was standing behind them, ready to join in, but several of Chen's minions had appeared behind them. They dragged the furious ninja back into a chair and strapped him in. 

"GO, JAY! HURRY UP!" he called, still struggling against his bonds.

"I KNOW, I KNOW!" Jay was shrieking while knocking over chairs. "I CAN'T WORK MUCH FASTER!"

But suddenly the dark side of Kai was in front of him, copying Jay's movements and looking through the obstacles. 

Jay froze in terror as the red ninja stopped and straightened up.

Kai turned around with the jade blade in his hand. His lips turned up in a grin, but the smile never reached his empty red eyes. The sinister smirk sent shivers down Jay's back. The ninja of lightning stared into his friend's cold expression, wishing he could disappear like Shade. 

"YOU STARTED THE WHOLE THING," the red ninja growled in a voice that wasn't his own. It sounded hollow and raspy. He pointed the blade at his target, ready to strike. "IF YOU HADN'T JOINED SENSEI WU, THE OTHER NINJA, AND ME, NONE OF THIS WOULD HAVE HAPPENED.

"W-what?" Jay looked confused and frightened. "I don't understand!"

"OF COURSE YOU DON'T." He scowled. "YOU NEVER UNDERSTAND."

Jay backed up a pace. "K-Kai... This isn't you!"

Kai laughed with no sign of humor and drove the blade closer to Jay's rapidly beating heart. 

"Oh, but it is me." He paused, cocking his head to one side in a sign of bemusement. 

"I'm just a bit..." He dug his weapon into Jay's chest, causing the blue ninja to stumble backwards with a cry of anguish. 

"...different."

"KAI HAS WON THIS ROUND!" Chen yelled through the speakers. "MASTER OF LIGHTNING... LOSES!"

Cole's mouth hung open in a silent scream as Jay fell to the ground. Tears streamed down his face. 

"KAI! WHAT HAVE YOU DONE?!" He yelled in agony, unable to suppress his emotions. "WHAT HAVE YOU DONE?!"

In the background, Chen whispered something to Clouse.

Suddenly, Kai's face cleared up and he came back to his regular self. He gasped as he saw Jay lying before him, a deep wound in his chest.

"W-what? Jay!" he collapsed next to his dying friend, checking his pulse to see if he was still breathing. He had no memory of what had happened.

Chen's minions let Cole go, and he charged to Jay's side, fearing the worst. "Jay...."

Kai stared at Cole in confusion with a silent question, tears starting to come to his eyes. 

Cole started to get angry, then saw that it wasn't Kai's fault and hung his head. 

"It.. it doesn't matter right now. Jay.. Jay doesn't have much longer. We need help."

Jay's eyes closed and he moaned quietly. "Ung.... C-Cole..."

Cole was instantly alert. "Jay! Jay, you're going to be fine! You're going to be—"

"W-what..." Jay cringed as a wave of pain passed. "What happened... to... to K-Kai?"

The red ninja sobbed, "I'm right here, Jay."

"Don't worry, buddy, he's back to normal. As you will be soon," Cole added sorrowfully, only half believing it.

The master of lightning shuddered. "I.. I..."

"Lay still, Jay.." Cole placed his hand on Jay's shoulder to prevent him from getting up.

"It- it's not y-your.... fault.. Kai..."

Kai wasn't sure what to say. 

"...Jay?"

"..What, Kai...?" he groaned.

"I'm sorry." the red ninja whispered, stroking Jay's bangs out of his face.

The dying ninja smiled. "...I... forgive... y-you..."

Jay shuddered once before falling into the void of darkness.