I'm not sure if Mushu is doing well. I put him back into the 10 gallon last night and he stayed mostly at the bottom. I thought it may have been the stress of the move despite being acclimated, but this morning he's still down there. When I turned the light on he was at the surface, but then he went right to the gravel.
His fins look better though. Most of the black on the edges are gone.
Maybe it's the filter's current. If he's still down there when I go back to my room I'll switch him to Hannibal's side (which has the heater, not the filter) and see if that changes anything.
Hannibal: Male Baby Betta of Unknown Fin Type
Tonraq: Male Half-moon Dragon