In the DBZ series South Supreme Kai isn't a transformation just a part of gohan buu to kid buu transformation. (he doesn't fight so you cant add him.(I hope you guys understand what im getting at.))
all the transformations and why there called that:
Number 1: Fat Buu
Reason: He is Fat.
(on a side note Fat Buu can also be called good buu because he turns good.)
Number 2: Evil Buu
Reason: they tell his name in the show from Dende I bleave "he split himself into good and evil."
Number 3: Super buu
Reason: I bleave the narrorator called him super buu at the end of an episode.
Number 4: Fusion Buu
Reason: He can not be called Gotenks Buu because if you recall he absorbed Piccolo at the same time.
(Besides doesn't Fusion Buu sound better to you?)
Number 5: Gohan Buu
Reason: He absorbed only Gohan this time I can't really think of a better reason.
Number 6: Kid Buu
Reason: It's the name of the saga do I need a better reason? (ill give you one if you want.)
Take this to heart guys its all true I've done my research.