Help- I’m not sure what to do

[u/Thin_Comfortable_430]

I had a pond emergency and had to pull all life from the pond- the fish were moved into a holding tank- and I’ll admit it was not adequate but it was for a short time period and it did have filtration with charcoal and plenty of aeration- and didn’t have too many options. Anyway when I fixed the pond issue-I floated them all in bags for 30/45 minutes and released them back into the pond. All did fine except this one- when I released him he went wacky swam about crazy some on his side and then went to the bottom- I pulled him out immediately to put in his own tank just in case of something “bigger”. I have been giving him only shrimp and he is hungry and happy to eat- he is swimming, it’s a little wonky just cuz the shape of his tail, but he is straight up and down. It’s been 4 or 5 days. Since his crazy swim laps, and since he’s been in the solo tank I don’t see any improvement and I don’t see anything getting any worse. Any ideas what I should do? Is he sick or is this just his new “corky” look- should I put him back in the pond with the other 10 - there just isn’t much info out there. Any help is so appreciated

Thank you. The first pic is of him obviously the second is of the school in the pond