who would win Keizer Ghidorah or King Ghidorah?

 I still see no evidence of how or why Kezer or hesei could regenerate, just theory, give me some facts please.

None of Toho's source books cite regeneration as an ability for Keizer Ghidorah. He does not have it.

Ummmmm nvm I guess because both ghidorah’s have good durability so I guess they don’t need regeneration...