the timeline and all sounds great! i like the sound of it being a first face-to-face meeting (though they could have heard of one another, especially mika hearing of levi's prowess as captain) and generalized bonding to lead into a mentor/student scenario... i feel like they have the same blase exterior that turns into zero-chill-when-fighting sort of thing going on, which would be fun to delve into? once mika decides to follow someone he gets scary intense and loyal, and will go full bullshit shounen rage to protect them.

at first he might come off as weird (weird kids in my aot, you don't say) because he seems kind of mellow and likes to snack at inopportune times and be off training by himself a lot. so his reputation wouldn't precede him by much, if that makes sense?

BUT GET HIM GOING AND IT'S A DIFFERENT STORY...

i was thinking it'd be neat to give him motivation in having him be separated from his orga-figure early on, and having him be so frighteningly intent on surviving so he can find them. then he starts bonding to levi, oops