The slider and the mutant (Feral Leo x Reader)

The Weirdest Reunion

~Y/N~
"LEO!" I heard Mikey's faint voice scream from across the lair, what a great way to ruin a good night's sleep. Speaking of which, has Mikey finally gone to sleep? Maybe he had a nightmare. I sat up from Leo's bed, I've slept in it ever since he left, I couldn't bring myself to clean his room either, I left everything the exact same so I'd had some memory of him.
I got out of bed and got dressed and put on some slippers, then I made my way to Mikey's room.
"Mikey, are you in there?" I called.
"Y/N!" Mikey's voice sounded panicked. "GET IN HERE! QUICK!" He shouted.
I ran into his room.
Oh.
My.
God.
"Mikey you son of a bitch! You did it!" I cheered.
Mikey opened another portal to the Prison Dimension.
I ran over to where he was, Mikey looked awful, he had very heavy bags underneath his eyes and they were bloodshot as well, perhaps from crying?
There he was, Leo, floating around, whipping his head in every direction possible. My ears raised upwards with excitement.
"What's going on?!" I heard everybody else burst into Mikey's room, where they stood there and gawked at what he did.
"LEO! I'M HERE!" I frantically called out, could it be? Mikey actually did it. He opened another portal and we would finally be reunited with the cocky turtle again.
Leo snapped his head in my direction, his eyes, his pupils were small and cat-like slits, I swear to god I saw them soften for a moment, he was beefier than usual, and he had a crazed look on his face. He made spastic movements to get closer to the portal, I could hear Mikey's breaths wavering, he was soon to collapse.
"Raph!" I shout, "Grab your tonfas and get him out of there!"
Raph was already a step ahead of me as he immediately did what he was told and reached a mystic hand out towards Leo.
Instead of grabbing Raph's hand, Leo climbed on top of it and ran towards us on all fours, like a frog. My ears remained shot upwards at the sight. What was he doing? Why was he acting like this?
Leo lunged towards the portal and shot out of it like a canon, pinning me on the ground and hissing at the others as he hovered over me.
"Leo! What are you doing?!" I shouted. No response, just more hisses and growls as he swatted at his family and Casey, who was staring at Leo in disbelief.
"SENSEI!" Casey reached a hand out to Leo, who swatted it away in response, his tiny tail was raised, opposing a threat to the animals and human.
Leo stepped on one of my ears as he stepped to everybody else, making me emit a sharp yelp.
"Leo! You're hurting me!" I cried. But he didn't listen, whatever happened in the Prison Dimension really broke him. He was acting like a wild bobcat or something.
Leo crouched down on his hind legs and covered me with his arms.
Fzzt!
I heard something strike Leo, who let out a quiet whimper. I wiped the tears out my eyes and saw that Donnie was holding his tranquilizer gun, and that he had shot Leo on the neck with it. He slowly slid off of me and fell to the side.
"Nice going Dee!" Raph cheered.
Thud
I looked over at Mikey, the portal closed but he was collapsed on the ground with severe lighting shaped burn marks on his arms, barely moving.
"MichealAngelo!" Splinter shouted, rushing over to take care of his youngest son. I looked back at Leo, who was sprawled out in the floor with a giant tranquilizer dart sticking out of his neck, forced to be put to sleep. This was too much, I couldn't take it anymore, my head started spinning, my ears were ringing, my vision is blurry. I couldn't think straight.
"Y/N?"
Thud

~Donnie~
What the-? What the hell is going on here? Leo's acting like a wild beast, Mikey managed to open a portal and free Leo and he passed out with severe burns on his arms, and Y/N is passed out on the floor too!
Leo's back! I usually don't feel anything but seeing my excessively annoying twin sparked tears of joy to stream down my face as I wrapped the sleeping turtle in a tight hug, letting everything come out.
"Ohmigosh I'm so glad you're okay! Don't ever do that to me again do you hear me?! I will put a leash on you if I have to!" I said through sobs, my head hurt from crying so much. Did I really miss him that much? Did I miss his cockiness, his really bad jokes, his giant ego, I couldn't have missed all of it that much.
I felt a hand be placed on my shoulder and I turned to see Raph kneeling next to me with a warm smile. Before looking at Leo and embracing him in a hug as well. His tail wrapping around me and my older twin.