1-4 star monsters require no tributes
5-6 require 1 tribute
7+ requires 2 tributes (unless stated on the card since some can require 3)
summoned skull falls in the 5-6 list meaning he requires only 1 tribute the reason why he was only a 6 star compared to something like dark magican was because of his def points being low at only 1200.
Anonymous
PK
