Sliver (Mirage)

The Sliver is a super villain Rat from an alternate reality. He is Splinter's evil alternate dimension counterpart and the grueling, destructive former sensei of the Super Turtles. His blind loyalty to his Master Shreddarius has put him at odds with his students, and he has become one of their major, though reluctant foes.

Mirage
The brilliant but conniving Dr.Shreddarius's creates The Terrorkinetics. These robotic protectors were commissioned by the corrupt Chairman Lucks to defend the Earth from supposed alien Invaders. In reality, they were constructs of evil design.

Lucks, a World Unifying Leader, had a definitive hold on this universes' power and was untrustworthy. Shreddarius own private experiments included four Turtle Super Soldiers in case Lucks decided to double-cross his scientific friend and betray their common beneficiary: Griddex, Blobboid, Graviturtle, and Shellectro, who would eventually band together as The Super Turtles. However, the chemicals and experiments eventually became unstable, and an explosion rendered Shreddarius severely disabled. A somewhat familiar lab rat licking the wounds and absorbing the chemicals on Shreddarius would mutate into the militant master, The Sliver.

Unlike the warm, caring, nurturing, disciplined and kind wisdom and love conveyed to the Turtles by Master Splinter, Master Sliver is cold and relentlessness in his teachings. A harsh taskmaster, his treacherous methods in training Shredderius's Super Turtles almost destroyed them numerous times in the insane effort for them to become the ' Ultimate Soldiers`.

Two rebel leaders, Case and O'Malley, would convince the Super Turtles of the truth behind Luck's evil, twisted hold on power and Shreddarius's subservience to maintain it. Sadly, Master Sliver was so blindly obedient to mad Doctor, he would not waiver that loyalty. Defeated briefly by his former students in time, yet independent from his Master Shreddarius, The Sliver would return more powerful than ever.

2003 series
In another universe, where the Turtles are superheroes instead of ninjas, their master, referred to as the Sliver, was initially their foster father but was eventually corrupted by evil. When Michelangelo was stranded in this parallel dimension by the fused Ultimate Ninja and Drako, Sliver was planing to wipe out humanity with the Penultimate Nullificator. However, because the device destroy all life on the planet, the Sliver modified it so that his tower and everything inside would be spared. He also set a trap for the Super Turtles, planning on turning them to the side of evil once the Nullificator was set off; he caught them in a Utrominium cage that proved impervious to their powers.

However, Michelangelo, who had accompanied the Super Turtles, came up with a plan to set them free. By having Blobboid pose as him, he tricked the Sliver into thinking them in Mikey's home universe, he and his brothers ruled the Earth and that they were loyal to their master. When the Sliver released 'Mikey', Blobboid revealed himself and snatched away his control cane, releasing the other turtles from the cage. Unfortunately, the Sliver had the same powers the Super Turtles had and had mastered them to a degree which made him superior to his students.

With the Super Turtles incapacitated, Mikey was left to face the Sliver. Using his ninja skills, he trapped the Sliver in his own cage. Unfortunately, the Nullificator was still set to go off. Luckily, Mikey figured that they could reverse its function to go off inside the tower. Shellectro manages to reverse the device, instead of destroying the world outside the tower. The Super Turtles escaped before the nullificator destroyed the tower with the Sliver inside it, while Mikey was pulled away by the efforts of his brother Leonardo to reunite his family.

Video Games
In Teenage Mutant Ninja Turtles 3: Mutant Nightmare The Sliver makes a guest appearance as a boss in a later shooting, first-person perspective portion of the game. Similar to the effect of the episode "Reality Check", the Turtles are blasted into other dimensions by Ultimate Drako. However, in the game the Teens fight in each universe and face off against The Sliver together.