Betta Fish: I wouldn’t have bet a dollar on him making it

My beloved betta Stan got himself absolutely MANGLED on God kkoes what in his tank and I thought for sure he was done for. But with advice from this awesome community he's survived and thrived and he's growing back his fins.
Eventually he'll go back to his old tank ( I've removed anything I suspected of being responsible for his injuries but I still have no idea what he did or how) but for now he's staying in his hospital tank and getting spoiled.