Giygas isn't the best villain, but he's up for one of the most tragic.
Him and Claus suffered a lot, but while Claus didn't have much free will in the beginning and managed to save everyone by offing himself, Porky tampered with Giygas while he was in a state of uncontrollable mindlessness from his extreme guilt. When the Devil Machine turned off, he was in constant pain in agony in a form he couldn't control with extreme power he probably didn't want. His father betrayed his whole species, he did what he thought was right to keep his own kind away from potential danger. And in turn, his own guilt for the kind he tried to erase destroyed his mind and body. Claus didn't have much of a choice in what was in the right direction, but Giygas had his fate altered to the worst end possible.
Porky's antics alone make him vicious and probably one of the most evil villains, I'd say more evil than
.
but nothing can beat Black Shadow he's just too fun