Greatest hater

What manga/hwa/hua and anime characters do you think deserve the title of "Greatest Hater", and I don't mean a character who when you get down to the bottom of it, is just a love rival or someone with an opposing view/belief(no matter how big or impactful), that turns them into an antagonist etc. I mean someone who hates someone with a deep jealousy, envy, or pride that's out of this world crazy, im talking about dog crap crazy.