*sigh*

This is something that makes logic face palm.

The evil protagonist always seems to hate the main character because... Well... Just for the sake of it.

This is something authors do almost all the time. They need a villain, every story does, but seriously? Make them hate the main character just for the sake of having a villain in the story?! That's lazy! Hence why the main character should have flaws, so then the villain can have something to hate on the main character, it isn't that hard.

Example:
Mary Sue is approaching me with Gary Stu on her side. Ugh I hate her. "Why do you hate Mary Sue?" Gary Stu asks me with his mainly voice. "None of your business!" I say. "Tell me!" Mary Sue says. "Uhh... Well you see... Uhh..." I don't answer her because I have no idea why I hate her. I just do.

I'm OK with the evil protagonist hate the main character because she's jealous that the bad boy loves the main character instead of her, but have her hate the main character for no reason is lazy. Just lazy.

Also, don't make her blonde with blue eyes. Or don't make her a make-up maniac. It's so annoying when the villain is like that. You can make her/him a person who loves video games, or sports! It's not that hard. :|