Zemus/Zeromus from FFIV. Zemus if absolutely full of anger and hate. In fact, the personification of his hate (Zeromus) is stronger than himself. (And is one ugly Sob). It even said that it would destroy everything until there is nothing left. Either him, or Neo Exdeath from FFV, who wants to Erase everything so then he can erase himself. Weather or not they have actual motives behind their goals other than hate or insanity, they both still wanted everything destroyed/erase from existance, and would stop at nothing to achieve that.