For those of you who can't read between the lines.

Chac is the level . . . 60? 80? Boss in the via infinito.

He is a basalisk type, so to oversoul him you can go and fight any of the big nasty buggers, but the only ones I remember are on djose road/mushroom rock xd
Level 80, you can also fight them in Bikanel.
I guess they don't teach your how to compare and contrast in school. Soon they won't even teach you how to undo a bra in health class.

Chac is the boss on floor 80. He is a basilisk type. Gucamatz (note: I said Gucumatz not Chac) can be fought on Mushroom Rock Road AND BIKANEL.