Mr. Nitrogen (Sequel to Leonardo the Nightwatcher)

Mutation

A few hours later, Garrett felt the urge to use the bathroom. He got out of the hospital bed and went into the bathroom in his room. As he began to pee, he thought about Fluttershy, and his friends and family. He thought of how lucky he was to have survived this freak accident. He figured he'd want to tell Fluttershy about his feelings for her. Call it a life's too short thing, but he wanted to make each and every moment with her count. He then began to wash his hands. He noticed the water was cold, but not irritating cold or painful cold. But much to Garrett's shock, the water in the sink literally began to freeze into solid. Garrett was confused. "What the?!?!?!" he said aloud, then noticed his breath was letting out a fog. He looked at his hands. His usual skin tone turned into a pale white, as if they were being frostbitten. He then looked at his appearance in the mirror. Even his usual fiery red and yellow hair was a snowy white! His cyan eyes lost all its color, and even the whites in his eyes were replaced with a frosty blue. They were almost like the type of pupil free eye slits a superhero like Batman or Deadpool would have on their mask. 

"W-what's happening to me?!?!?!?!" Garrett asked as he looked at his new appearance in the mirror, gripping the sink in fear. But the moment he touched the entire sink, it froze like nitrogen freezing a sink. Garrett screamed in terror, and then ran out into a wall. Upon contact the wall froze revealing frost, then broke away as Garrett broke out of the wall as he ran in terror from his newfound appearance and inexplicable powers! Meanwhile, Donnie was on the phone outside Garrett's room. He was calling Rarity on his phone. "Hello Rarity? Yeah, it's me babe. Look, I was at the hospital visiting Garrett- Yeah, he's okay... He told me about what happened between you and Blueblood.... Babe, I didn't know... Yeah, he hurt Garrett... Rarity, I want you to know I'm here for you, always... Yes, I'll bitchslap him. Alright, I love you babe. Talk to you soon." He hung up, then he heard Garrett's screams of terror. "Garrett!" he said in concern as he and the brothers went into the hospital room. The room was empty. "Where'd he go?" Mikey asked, confused. Raph shivered and said, "Is it just me, or did it get cold in here?" They saw the root of the coldness, and found the bathroom looked like a frozen room. "What happened here?" asked Leo.

Meanwhile, Garrett was in a corner on the streets, wondering what happened to him. "What am I?" he asked himself, "What was in that nitrogen? Do I have some sort of Midas touch? Except, does everything I touch freezes like nitrogen?" This all terrified him. Suddenly, he saw a mugger harassing an old man, holding a gun against him. Garrett decided to stop the mugger. "Hey, mugger jerk!" said Garrett, getting the mugger's attention. He grabbed his gun, and the gun immediately froze, and Garrett crumpled the frozen gun with his cold hands. "You want to suffer the way your gun did?" he asked, causing the mugger to shake his head no, "then leave the old man alone! Go on, skedaddle!" The mugger then ran away. The old man looked at Garrett and said, "Thank you kind sir! Bless you!" Garrett smiled. True, his powers were inexplicably terrifying, but maybe he could use them responsibly.