Arthas is one of my favourite villains in anything anywhere ever. He's up there with KH1 Ansem and Sephiroth, and so is Kel'Thuzad--and it's because they all have this great enemy-within facet to them. They're skilled at reading people, or telepaths/empaths, or something--they can get under your skin or into your head--and they're all associated with some insidious pathogen-like thing (Arthas and KT==plague, Ansem==sudden heartlessness epidemic, Seph==Jenova cooties).

Heck--Castlevania!Dracula falls into this category, too--

I love that they get so personal, that they make it a game to GET to people. sgkjjlsdfgsdf incoherent fangirly squee everywhere.

And they all started out as ordinary-exceptional people and then everything went to balls.

tl;dr yeah I could nerd like this for ages XD