Is this a tumor? Please help be determine the best course of action for this hot mess.

[Wyorp Rock]

I think it's looking better.
I'd continue treating like you are.

To me, it looks like it's injury from all his tail feathers being removed (ripped out?). That would leave a wound for sure.

 

[coach723]

I agree, it looks less swollen than when you started. Hope it continues to improve.