I'm just thinking about how, most of the time, when we've seen Katsuki smile, it's often for the purpose of posturing. Always laced with a little bit of snark. A smirk, a menacing sneer, a show of teeth if only to remind anyone who's watching that this dog does, in fact, bite.
But in this frame — right after All Might offers a makeshift splint for Katsuki's twisted, mangled arm — Katsuki smiles. No grit or goading here. Just what very well might be the softest expression we've ever seen him wear.
Is it because he's happy to be alive? Because he feels proud to protect his childhood Hero? Because he's grateful to still be in the fight?
I honestly haven't reread this chapter enough to have a solid answer, but I just can't stop coming back to this frame. I reckon it's sort of all of the above; once revived, one of the first things Katsuki says is "Thank you" to Edgeshot. All Might offers his help in this scene because he knows there's more fighting to be done, and Katsuki is the one who's going to step back up to the plate.
Part of me wonders if, at this stage in his development — ya know, post the whole "Izuku, I won't get in your way anymore" thing — he's just happy to be of service.
But he looks happy.
This little motherfucker died. And he looks genuinely happy.
The fic by Rockity Sock is still an unpublished WIP so far, but it's really nice and will hopefully be completed and published later.
It begins at the end of the Ultimate Enemy episode, with Dan getting trapped in the thermos. And... I'm not sure how much I can say without spoiling it, but a lot of really cool stuff happens. It's a psychological type of fic, about different types of prisons and punishments, and has time stuff and pocket dimensions, and redemption stuff. (I was only planning on drawing one illustration for IB, but when I saw the WIP, I wanted to see so many things animated. So many awesome visuals. I wish I could've animated them all.)
This is the part I did animate:
He just walked for now, searching for the tiniest crack. The darkness went on for seemingly forever though, and no matter how far he walked it kept on going
Dan kept moving
He tried his best to break through the walls but every ectoblast he formed fizzled out. Fading into the darkness.
Oh, now it makes sense.
His powers are being limited, it takes him a few more tries to believe it. The fact that he’s trapped with nothing whatsoever. Endless hours spent, and wasted. Powers he has built up from the ground with no mentor, ones he trained endlessly after a decade.
Gone, disappeared, muffled. Limited. Dan let out a laugh, one with no humor. A laugh that turned into a cackle, he couldn’t stop.
Here's Rockity Sock's AO3 account: https://archiveofourown.org/users/rockitysockity and tumblr account: https://rockitysock.tumblr.com/
(I also uploaded the video on deviantArt and YouTube)