I just found Arthas listed as a Chinese name. This made me laugh. Arthas is a fictional character from World of Warcraft, an online multiplayer game. It doesn't have any meaning other than that. Arthas Menethil is a tragic figure in game lore who ultimately becomes the arch-villain and leader of the undead hordes.
http://wowwiki.wikia.com/wiki/Arthas_MenethilNaming a child after him is up to the parent, but, er...it's not a Chinese name no matter how you slice it.