The fic by Rockity Sock is still an unpublished WIP so far, but it's really nice and will hopefully be completed and published later.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)