It's been days and you still can't figure out why Okarun is stuck in Turbo Granny mode. The only bright side to the situation is he doesn't seem to be affected negatively by it, so his human form should be fine

"Bad news, babe" Okarun's voice is raspy and tried as always, his form slumped over as he leans against the door frame "Momo wasn't able to help.. said something about aura? Total bummer"

Unless you find a way to get him back, you're stuck with his new personality... But maybe you like him more this way