User blog comment:SilverHexxitFights/Which is Terraria's Hardest Boss?/@comment-24151017-20131111054633/@comment-1466854-20131111070326

Paladin and Ice Golem are considered minibosses. Dungeon Guardian isn't intended to be killable, thus he doesn't really count. His entire purpose is to be horribly unfair and make you not want to do that terrible thing you just tried to do.