Tomura hates a lot of things: heroes in general, All Might in particular, losing, promising games that crash and burn in the final act, his own quirk sometimes and... interacting with children.
It's not so much that he hates kids but... they don't like him and he doesn't know how to fix that. It makes him uncomfortable. People are only supposed to cry when he's trying to make them cry, not when he tries a non-threatening smile.
Point is, he hasn't been going out of his way to interact with Eri, the child Toga dragged home like a semi-feral cat proudly presenting a dead mouse to their unimpressed human. He hasn't made her cry yet but he feels like he's walking on glass around her and it's stressful. Spinner seems to agree, making excuses and holing up in his room more often than not. It's not... ideal.
They're laying low which means they hardly leave the hideout and the itch to do something is getting worse. He needs to let off some steam. He can't realistically do that physically so video games it is. Spinner is the only semi-cultured one around.
Mr. Compress likes to wax poetic about how back in his day cards were prime entertainment and the youth just isn't grateful anymore or something, Tomura only ever half listens to him. No well adjusted child was playing with a deck of cards in his day, Mr. Compress is not that old. Toga plays violent games occasionally but usually quits before the hour is up complaining about "the blood not being pretty enough." Twice doesn't focus very well and hardly tries. Dabi never bothers either, choosing to use his ignorance to spite Tomura.
So Tomura proposes a multiplayer fighting game and they head down the to main area of the base. Luckily, no one else is around at the moment and he can hear Spinner's sigh of relief at the lack of little girl. No matter how weird quirks have gotten, Tomura knows that mutation quirks still face a lot of discrimination. Spinner has sheepishly mentioned once that kids sometimes don't react well to his appearance.
They manage a few rounds before they're interrupted by a small form popping up between them from behind the couch. Neither one of them had heard her coming, Spinner lets out a rather undignified yelp.
"Fuck! Eri, what are you doing here?"
"I'm bored, what are you doing?"
"None of your business brat. Go bother Toga."
"I can't, she's busy."
She clammers over the top of the couch and sits between them, looking curiously at the screen now flashing a game over sign.
"Can I play with you?"
Tomura makes uncomfortable eye contact with Spinner over her head. They probably shouldn't let the small traumatized child play the ultra-realistic fighting game until she's at least... ten? What's the rating again? Whatever, Spinner slowly looks away.
"Um, Eri, maybe we could play a different game?" Spinner hedges.
"Is it any fun?" She tilts her head in a way that Tomura should not find as cute as he does.
"Sure, I'll go find something." Tomura carefully riffles through his collection until he finds some group racing game. He never played it much, Kurogiri had bought it in the hopes of getting him to socialize with his team. They'd promptly given up after the first time Dabi melted a controller and Toga's stabbing threats got slightly too serious-sounding for comfort. If Tomura remembers correctly Spinner wasn't driven to homicide by the experience so it should be fine. They're still unclear on Eri's quirk but she probably won't kill anyone if she loses. She's a polite child like that.
"Alright, here we go."
Tomura sets things up and tracks down a controller while Spinner starts explaining the characters. Eri requests an explanation of each one, Spinner is initially fidgety and obviously uncomfortable but as she fails to react beyond wide-eyed questions about the game begins to relax.
He sits back down and together they explain how to move and which buttons do what.
She's absolutely terrible.
They have to take it easy so she doesn't lose almost immediately. She runs into walls and hits every obstacle. They readjust the settings to be easier and she hits almost all the obstacles instead. Tomura is not having a great time and he doubts Spinner is doing much better but her eyes are focused and she's clearly doing her best. He can't kick her off because she's trash.
Take that world, Shigaraki Tomura knows enough about children to not kick them off a game just cause they're bad at it.
He feels like that might not be impressive.
Oh well, he can tell Spinner is softening at her excitement over finally coming in second to last place. Honestly, his temper isn't flaring like it normally would at being forced to play with some noob. He takes a few moments to breathe deeply and continues to indulge her.
It's annoying but not enough to get him in a murdering mood.
"Are there other games?"
"Sure, there's a lot of stuff out there. Do you want to try something else?"
She nods with determination. Tomura stiffles a rude snort at her serious look and fetches a handheld gaming console and a game he remembers Kurogiri getting him in an effort to find non-violent outlets. He didn't agree with Tomura's argument that all video games are a non-violent outlet and proposed a calm simulation game with animal villagers. Tomura never had the patience for it but it's probably a good choice for Eri. He's fairly certain there's not homicidal twist or anything.
He sets her up with it and smiles at the stars in her eyes as she explores the world and characters with glee. She looks up at him and doesn't flinch. Spinner tracks down a less bloody fighting game and they're soon back at it as competitively as before.
It's nice, sitting with his... comrade? friend? and letting off some steam. He doesn't even mind the little body pressed up between both of them. Tomura doesn't like physical contact most of the time, it makes him uncomfortable. He doesn't like children most of the time either for similar reasons but now that he's actually spending time with her, he finds that he doesn't really mind.