Disclaimer: I don't own the TMNT comics. Sometimes that makes me cry.
Author's Notes: This is based off of the concept in the Volume One Mirage comics for TMNT, specifically in issues 10 and 11. For those who don't remember them, it's when Leo gets the crap beat out of him by the Foot during Christmas, nearly dies, and recovers at the farmhouse. If you haven't read the comics, I just wrote this because I found it both suitable for Mike's character in the comics and interesting that he was the one to end up lashing out violently afterwards. It was hinted at, but never fully followed. Mike in the comics is a touch darker and more temperamental than his show counterpart.
I hope y'all enjoy! Thank you so much for reading, as always. Your support always keeps me in this fandom.
In the winter, as Leo vanishes ever more frequently into the snowfall surrounding the farmhouse, Mike finds solace in the beating.
It isn't training. Mike knows full well the practiced, balanced art of the ninja, where his normally fleeting attention span has been stretched by his father's careful and nimble fingers. The art is precise. Purposeful. It has no place in this new world, where the homes of friends are eaten by fire and foe, and where his older brother abandons them as he does himself to his demons. Master Splinter must sense it—he spends most of his time in the attic, meditating, or gently counseling April. Raph broods in his own way until Casey drags him, usually bodily, out of it. Don invents and, when that grows stale, writes. Mike used to write to release things.
But words are way too stupid, shallow, and weak for Mike right now.
So he beats things up.
There's no other way to describe it. He punches the heavy sacks he hangs in the barn, he swings high kicks until the ropes creak and break. He pummels the hay stacks until straw flies everywhere. He breaks the ladder with his forearms. He bruises and bends and splits and gouges. He bites his tongue until it bleeds and snarls soundlessly in the dark as he keeps at it, always moving, burning with sweat and muscle pain and that perfectly final edge he can never quite reach.
Raph, when he enters the barn, only leans against a stall with his arms crossed. He watches and snorts in approval for all the wrong reasons. Don tries to talk to Mike about it, but Mike ignores him, and so it becomes another little reel of words typed out when Don is too close to bursting. Master Splinter leaves him to flounder. Mike, when he thinks about it, isn't nearly as surprised by that as he should be.
Leo comes in and holds the punching bag, sometimes. He never says anything, not even when Mikey snaps at him to go away. Not even the one time that Mike punches him instead of the bag.
(Leo was weak. That's what got them into this mess. It's Leo's fault. Leo got his shell kicked and now he's abandoned them, because the Leo that Mike remembers isn't really there, not where he used to be. This Leo is pale, like the landscape he disappears into so often, and acts as though he's lost. Mike hates him. Mike sometimes wishes he would just stay in the woods and never come back. So weak. Their family, splintered in two from one night, is so weak. Leo isn't good enough. He'd been the best, but then it wasn't enough and he'd been thrown into the window like a deadweight, all broken and messed up, and Mike had wanted to kill all of them for that brief second when he whirled around to face the enemy. Just beat their faces in, like Leo's. He hates them hates hates hates weak hates himself—)
Eventually, though, spring comes. Mike's anger burns out; first as a desperate, grasping flare and then into a quiet simmer. His strikes slow again, his footwork becomes clumsy. He clutches the punching bag, panting, and realizes the wet streaks down his face aren't sweat, but tears. The barn doors open again and sunlight streams down into the shadows, faint but warm. Mike finds himself settling again into place—the world stops careening around him and for the first time, he finds himself joking with Raph again, harassing Don during his brother's experiments, and making smiles for April. Master Splinter nods to him across the breakfast table one morning and Mike lets the last of his fury slip out of his fingers to pool on the kitchen tiles. It's not his anymore. It's left him changed, and older, and ready, but there are some things that stay out their welcome too long of a time.
He can touch Leo now. So he does, first by brushing his elbow, then by clapping his shoulder. When his heart wells too high, he pulls Leo into a hug and laughs when his oldest brother sputters. It is familiar, disarming, and painful like hope.
Next winter, as Leo spends less time in the snow and creeps back into their lives—so does Mike, ready to receive him.