Installment one.
Please R&R.
I do not own TMNT.

New York City was quiet. The streets were barren since criminals had finally gotten wise and learned to hole up unless absolutely necessary. Too many of their own had been killed while walking the streets. Even disguises and protective clothing had not kept the avenger away. Many had almost come to believe that the criminals had died of supernatural means, while more practical thinkers believed that there was a mole on the inside. This left many crime lords with major rebellions and severe bloodshed on their hands from within their own ranks.
A lone shadow kept watch over the city from the top of the former foot headquarters. Shredder had been vanquished nearly seven years ago and the residing foot had either been killed or fled for their lives following an epic battle that nearly destroyed the tall tower. This shadow was the bloody avenger. He had long ago thrown away the rule that had previously governed him, fight hard but only to win. Never take a life unless necessary.
The less-than-human crime fighter smiled grimly. It seemed like it was always necessary, especially when it came down to keeping criminals off of the streets.
The vigilante suddenly launched himself into space and fell nearly thirty stories before landing lightly on the next roof. He raced across the rooftops, taking full advantage of everything that was offered him. He finally stopped, resting on a street lamp.
The minor scuffle that had attracted his attention appeared to be nothing more than an idiot purple dragon harassing a young woman. She tried to fight back but her efforts were weak.
The vigilante back flipped off of the lightpost and landed in a crouch. "Leave the lady alone." Two steps forward brought the crime fighter into the light, revealing him to his new victim. He stood about five and a half feet tall, but his most striking feature was that he was green. Closer inspection showed that his powerful hands only had three fingers and he had a turtle shell growing out of his back. He was, in fact, a turtle that had been mutated nearly twenty years ago by one of Shredder's experiments. How ironic that Shredder's creations ended up being his doom. His eyes, cold and hard as ice, sized up the thug through a black bandanna that encircled his head, a tribute to his past.
The purple dragon, instead of cowering in fear or running for his life, chuckled and brandished a large knife that he had hidden in the back of his pants.
The vigilante rolled his eyes. Why would anyone hide a knife in his pants? And did this guy really think that, with only that knife, he could defeat the one who took down Shredder's bodyguard, Hun, as well as most of the foot ninjas in his employ? The turtle cracked his knuckles, ready to have a little fun with the punk.
Suddenly, his ninja reflexes kicked in, causing him to duck as a chain with a heavy weight on the end flew harmlessly over his head. He turned to face this new attacker and smiled grimly. He was surrounded by purple dragons, each holding their weapon of choice. The knife wielder and young lady joined them, the woman pulling a short sword from a hidden sheath on her back.
The turtle drew a katana from his back and nunchuks from his belt. The katana for close range attacks and the nunchuks to ward off longer range ones. He fell into a defensive crouch, katana in front and nunchuks whirling above his head.
This would be his most challenging battle yet.