Oh jeez. Okay, the Triforce of Power enables Ganondorf to turn into Ganon. That doesn't mean he can't be Ganondorf as well. People think (and this is exclusable) that Link kills Ganondorf, then Ganon forms out of dead Ganondorf. What really happened is that the Triforce of Power makes its owner immortal (hence Ganon/dorf can never be killed, only sealed away or trapped), but when Link "killed" Ganondorf in Ocarina of Time, that marked when a normal person would have died, but shortly the Triforce of Power revives Ganondorf and he can now use it to turn into Ganon. And its obviously not permanent, when you beat Ganon (link impales him through the brain in the last cutscene), he turns back into his human form as Zelda and co are sealing him away. Anyway, so the only uncertainty is if Ganondorf can switch between forms at will. Probably not, or he'd have done it in Wind Waker (or maybe the devs were lazy), so it seems the transformation must be triggered by something, such as the severe beatdown administered by link or the anger and humiliation of being beaten by a kid.