Real talk, I think the thing that made unbound thresh feel off is just the splash art. Young face and the spectral ABS made him feel very off, add to that the model of thresh being very old and not allowing for a clean skin on LoL compared to wildrift and it made it feel underwhelming.
I feel that they should tweek his splash art again, I know people love to pretend pilosity is something dear to their heart but making him looking older/rougher would be perfect to make him less "Spectral spirit blossom" like.