TT is a bit tricky. He's pretty much unbeatable at the END of time. He's less powerful near the current timeline and was killed by Parallax, I believe, but still came back, because he can't be truly beat.
He's created his own pocket dimensions and can manipulate time with ease.
He's basically the embodiment of Entropy/Oblivion in some appearances, but his true origin is somewhat of a mystery. Unless you believe LO3W.
so I guess being killed by Monel is plain PIS and shouldn't be used as an example...Hell i wouldn't use the Galactus thing as example if Bill somehow won the fight.