Little-miss-irate wanted a one-shot from the "Mourning" universe, focusing on Leo avenging Mikey's death by slaying the Shredder and all his henchmen.

(cue Kill Bill theme! XD)

This chapter will be rated M due to disturbing content!

NOTE: There will probably be grammar mistakes which I will fix later.

He watched the sparks rise up from the fire and into the dark sky, along with his little brother's soul.

Standing next to him, his brother Donnie watched the burning with apathy. Since the night of Mikey's death, the genius Turtle became cold and emotionless, like a robot. He barely spoke to anyone and his auburn eyes were distant and dull.

April stood on the other side of him, sobbing for her little brother. Casey knelt on the ground, watching over the unconscious Raph. There were tears spilling out of the boy's eyes as well.

On the surface, Leo seemed calm and forlon, staring numbly at the burning pyre. But there was burning desire within him. A desire to avenge Mikey's death.

He left in the middle of the funeral, and April caught up with him and begged him to stay with his family in this time of mourning. But nothing would dissuade him from taking vengeance. Nothing.

Heads were going to roll tonight.

I swear, Mikey...I'll make them all pay.

"Do you think they'll be back?" Fishface turned to Rahzar as they stood guard outside Shredder's hideout. A bandage was taped onto his nose from Raphael breaking it yesterday.

Rahzar looked at his comrade. "Do I think who will be back?"

"The Turtles. Now that Shredder has killed one of them, you think they'll be back for blood?"

Rahzar jerked his head back and let out a raspy laugh. "For blood?! No way! They don't have it in them! Besides, we've broken them. They're too devastated to try and take us on."

"Hmmmm...I'm not so sure about that," Fishface said a bit nervously. "After all, these are the Turtles we're talking about."

The mutant dog wasn't the least bit fazed and sneered at Fishface. "You scared, Xever?"

"Perhaps a little," Fishface muttered, still looking around him cautiously.

Unbeknownst to them, as they continued to converse, a figure moved in the shadows, watching them with predatory white eyes. He slowly reached for the katanas behind his shell and unsheathed them. One of Rahzar's ears twitched at the hissing sound that they made and he whipped his head in its direction.

Fishface noticed Rahzar's alarmed expression and followed his gaze, but he saw nothing in the dark alley. "What is it? You hear something?"

Growling, Rahzar slowly crept toward the alley and bared his teeth. "Who's there?" he hissed. When no one answered, he took another step forward and sniffed for any strange scents. There was none. He slowly began to relax and turned back to Fishface. "False alarm. Heh. Maybe I am a bit nervous ab-"

Rahzar gasped as the tip of a sword suddenly went right through his chest. Blood spilled down his chin as he gurgled before he fell to the ground dead, the life in his golden eyes having faded away. Fishface stared on in horror as Leonardo slowly approached the body and pulled the sword out before flicking it. Some of the blood splattered onto Fishface's abdomen and face and he yelped and tried desperately to wipe it off of him.

"You..." Xever slowly backed away from the Turtle, "you killed him...!"

Leo only stared at him with cold white eyes. "So?" he casually said, as if killing Rahzar was as insignificant as squashing a fly.

That was when Fishface noticed that there was no one else around. "Wait...where are the two other Turtles?"

Leo shook his head. "It's just me tonight," he said.

This gave Fishface some confidence. After all, it was just one Turtle. If he was facing all four...er, three of them, then he'd be worried. But then again, Leonardo was supposed to be the most skilled fighter of the bunch, and it was obvious that he was out for blood. Putting on a brave face, he pulled out his butterfly knives and unfolded them, trying to still his shaking. "You're a fool. You can't take all of us on your own. I thought you learned that a few years back."

Leo merely smirked at him, although something about it sent chills down Xever's spine. "I'm the not the same as I was then. I guarantee you that."

Snarling, the fish mutant charged at Leo and viciously attacked him with his knife. But the master knife-fighter was no match for the former leader of the Ninja Turtles, for the latter dodged every swipe, punch, and kick. Never had Xever seen him move with such agility and speed, even in their most intensive of battles. In fact, it was as if Leo was merely toying with him.

But eventually Leo grew tried of playing and with one swipe sliced both of Fishface's arms. The fish mutant screamed shrilly as yellow blood gushed out of his wounds. He was too distracted by the overwhelming pain to notice Leo targeting his robotic legs. As soon as the legs were sliced off, Fishface dropped to the floor and flopped around like a regular fish.

The sight amused Leo and he chuckled cruelly as he stepped on Fishface's leg. "Now you really are a fish, Xever."

Despite the pain he was in, Fishface glared up hatefully at the Turtle. "You sadistic son of a...!"

The smile on Leo's face dropped. "I'm sadistic? Isn't that the pot calling the kettle black? Your master tortured Mikey to death, and you made us watch. Not only that but you also laughed at his suffering." He sheathed one sword but held onto the other, aiming it up at Fishface's chest. The frightening predatory smile slowly returned as he started to raise the sword a bit. "I'm only giving you a taste of your own medicine."

A horrendous scream filled the night sky as Leonardo preceded to gut Xever like a fish.

"You seem tense, Master."

Shredder slowly lifted his head and looked over at Tiger Claw, who stood beside his throne. Indeed, for some reason that he could not fathom, the monstrous mutant had been troubled since that fateful night. But he tried not to appear so in front of his henchmen. "I am fine, Claw. Just...a little tired."

Instead of the pressing the issue further, Tiger Claw merely nodded. Bebop and Rocksteady sat at the bottom of the stairs, casually chatting and joking with each other.

"So, Rock, think I should get a nose ring?" the scrawny pig asked his best friend. "You know, to add some style to my already awesome image?"

"I do not see any reason not to," the Russian rhino said with a smile.

A loud banging sound startled them both and nearly made them jump five feet off the ground. Tiger Claw instinctively reached for his pistol in his pouch while Shredder sat up straight in his throne. Hyperventilating, Baxter Stockman came flying into the room. He landed on the floor stumbling a bit and ran up to the stairs, looking up at his master with scared bug eyes.

"M-Master Sh-Shredder," Baxter stammered. "One of the-the Turtlezzzzz is here!"

Immediately Saki tensed. "What did you say?"

"Itzzzzz Leonardo, Master," the fly gulped. "He izzzzzz back and hezzzzzz m-mad! He-Hezzzz crazzzzzy-mad! Hezzzz aleady killed Rahzzzzzar and Fishface!"

Tiger Claw's eye widened. "Rahzar and Fishface...?" he whispered in awe. "They're both dead?"

Shredder couldn't believe what he was hearing. The Ninja Turtles...taking revenge? Wasn't that against their moral code? Or perhaps the they were even more dangerous and deadly than he had presumed?

No sooner had he finished that thought when Leo, himself, stepped out of the dark halls and into the room. Yellow blood, which obviously belonged to Fishface, was splattered all over his plastron. And his blank white eyes were so cold and bloodthirsty that it gave him the appearance of a demon. His lips curled into a snarl and he pointed a bloody sword at Shredder. "You're mine, Saki," he hissed. "Tonight will be your last."

Shredder got out of his throne and slowly made his way down the steps with Tiger Claw following close behind him. "You wish to avenge your brother's death on your own? Clearly you did not learn your lesson from last time." He turned to the mutant pig and rhino duo. "Bebop! Rocksteady! Make him suffer!"

Bebop gulped as he nervously approached the raging Turtle. "Uh, s-sure thing, boss!" He then activated his cloaking device, and the invisible pig circled his target.

Leo closed his eyes and calmly waited for the right opportunity to strike. When he felt Bebop's presence getting close enough, he twirled and struck him somewhere. The invisibility wore off immediately and Bebop fell to the ground, wailing and gripping his bleeding shoulder.

Rocksteady's eyes widened at the sight of his best friend badly injured. "BEBOP!" He roared in rage as he charged at the Turtle who dared to hurt the pig, his massive horn pointed at him.

Leo smirked and ran toward the charging rhino headfirst. He took one big leap and aimed the tip of his sword in between Rocksteady's eyes. There was a look of surprise on the rhino's face as the blade pierce right through his skull and brain.

Baxter put a deformed hand to his mouth in shock as Rocksteady dropped to the ground dead, and Leo pulled his katana out of his head. Tiger Claw was stunned. Bebop was moaning and sobbing for his dead friend. Shredder stared on impassively, before he turned to his faithful bodyguard and second-in-command.

"Tiger Claw, kill him."

Tiger Claw glanced over at his master in surprise before taking a deep breath and stepping down the stairs to confront the Turtle. He pulled out his pistol and immediately began firing. Of course Leo dodged every laser and knocked the gun out of Claw's hand. The tiger refused to back down and began to wildly kick and scratch at him.

At one point the razor-sharp claws of his metal hand managed to slice the blade of one of Leo's swords in half. Leo looked at what was left of his katana before narrowing his eyes in fury and taking one swipe of his other katana. He had sliced Tiger Claw's metal arm off, and before the tiger could get away in time, he sliced his other arm off.

Claw screamed in pain and dropped to his knees, completely armless now. Leo approached him and raised the sword over his head, preparing to execute the tiger.

In desperation, Claw turned to his master and looked at him with a pleading eye. "Master Shredder! Please! Don't let him-!"

Before he could finish, his head was sliced off his shoulders, and his body fell limp to the ground. Leo looked up at his two remaining targets and smirked. "Five down, two to go." He lazily rested his sword on his shoulder and slowly approached Stockman in a menacing manner.

Stockman began to back away, waving his hands out in front of him. "N-No! No, p-p-pleazzzz..." His large insect head was then sliced off his shoulders, and Leo stomped on it with all his might, causing yellow-green goo to splatter all over the floor.

Now only his main target remained standing. Even though Saki had this dreadful feeling that tonight would indeed be his last, he brushed that fear aside and chuckled. "You are a fool to think that you can defeat me on your own. But not even the four of you put together would give you an advantage over me. Not the slightest."

He expected the Turtle to disregard his statement and blindly charge at him. But instead he smirked and said, "You're right. That's why I'll cheat."

Leo then threw a small vial at the Shredder, who immediately reacted by swiping his hand at it before it could reach his face. The second the object shattered, a purplish gas was released and he unwillingly inhaled it all. He muscles suddenly stopped working and he was frozen stiff. No matter how hard his brain willed him to move, he could only stand with his arms hanging limp at his sides. He watched as Leo approached him with a malicious smile on his face.

"One of Donnie's latest inventions," he said. "A special kind of gas that causes complete paralysis. We've never actually tested it on anyone, though. So you're the first to experience it, and as we can see from the results, it actually does work and is a complete success."

He got up nose to nose with the Shredder, pointing the tip of his katana at the mutant's blue beating heart. "I could pierce that rotten heart of yours right now," he whispered venomously. "But even that wouldn't be enough. I am going to make sure that you suffer like you never have in your final moments, the same way you made my brother suffer."

During the next several minutes, all Shredder could do was watch helplessly as Leo eyed each body part and slashed it with his katana. His agonizing, inhuman screams echoed in the room and blue blood was splattered everywhere.

And Leo was laughing the whole time as though it was a game.

Eventually Shredder fell on his back, still paralyzed from the gas, but Leo did not stop torturing him. He weakly opened his glowing blue eyes and looked up at the Turtle that continued to stab at him.

"Ple...ease..." he rasped.

Leo stopped and leaned in close to Saki's face, eyes still white. "What's that?"

"Please..." Shredder said a little louder, "...kill...me..."

The corners of his mouth slowly lifted into a cruel, sadistic smile. "Kill you?" he chuckled. "No. No, you won't get off that easily, Saki."

...

After nearly thirty minutes of slashing, it was finally over. Oroku Saki had drawn his last breath. In Leo's hand was his blue heart that was no longer beating. The Turtle took in a deep breath and closed his eyes, lifting his head to the ceiling and ultimately to the place where his brother's soul resided.

"I did it, Mikey," he whispered. He opened his eyes and looked down at the heart in his hand. "But the war is far from over." He squished the organ and dropped it on the ground, deliberately stepping on it as he left the building.

Again, I am NOT taking any more requests at the moment, but reviews are always welcome! :)