How would Prime Mike Tyson do in the UFC? Would he become champion?

LOL no. MMA was essentially taught through the middle ages as a mix of boxing and wrestling combined with weapons. MMA began in "the west" as pankration.

 

Sure, but i think he means the MMA what we know today. And with "west" i guess he means especially the USA and western world.

Vale Tudo did exist in Brasil long time ago, in China they had Beimo, in Japan they had also free fight stuff, imo PRIDE was superior to the UFC in the early 00s, i always laugh when Dana slams Fedor for not have fought in the UFC.
It is an absolute american dream nonsense that Lesnar in 2009 or so would ever had a realistic chance to beat Fedor, even if Fedor was already slowly past prime then. But some Americans really believed this fairy tale in the late 00s and early 10s, until Lesnar lost to Cain.

This was a little OT. But i am sure he ment the MMA as we know today, and this was really unknown in the western world until the UFC was founded in 1993 by the Gracies and Art Davie.
Rorion once stated when he came first to the USA in 1979 nobody there knew the Gracie´s, BJJ or ever heard about Vale Tudo etc.