Ghetsis is the most evil and intimidating villain in the main series, with Cyrus being second. He's cunning, manipulative, narcissistic, insane and above all else, heartless. Unlike other villains, he has no good intentions or a tragic backstory. His only goal is to dominate and rule in the shadows simply because he believes he's the perfect being. He committed numerous terrible things, like abusing and brainwashing children, bombing Opelucid City in ice, torturing Kyurem, and attack the player. Even his own pokemon hates him. And the worst part is that Ghetsis always gets away in the end. That's why, in my opinion, Ghetsis is the best villain.