Skeletor
(Evil) Lord of destruction

Mini Comic Skeletor:

He came from another dimension, where others looked just like him.  His main goal was to find both halves of the power sword and join them together to enter Castle Grayskull and become king.

1980's Cartoon Skeletor:

Leader of a bunch of bumbling fools, he tries to get the secrets of  Castle Grayskull.

1980's Movie Skeletor:

Some guy who wants the ultimate power of the Universe.

2002 Skeletor:

Similar to the 1980, but in this one he was once Keldor, a blue skinner powerful guy, who was the mortal enemy of Randor, who is the current king and Father of Adam.

2009 Skeletor (Classics):

Real Name: Keldor™

Mortally wounded in battle with his half-brother Captain Randor™, Keldor™ turned to his dark-arts master Hordak™ to save his life. Merging Keldor™ with the extra-dimensional being Demo-Man™ from Despondos™, Keldor™ was forever changed into Skeletor®, Overlord of Evil™! He gathered together the greatest outcasts and evil warriors of Eternia® in his quest to gain entry into Castle Grayskull™ and obtain what he believes is the universe’s ultimate power source.