Doom

Doom is an entity in the 15 Keys universe that is intent on destruction, even going so far as to kill a rival species named the Prime Neocrities, who could have conquered the universe at a quicker pace than Doom could. Doom is russurected in 15 Keys 3 after the duel with the Kingdom, he proceeds to murder the first incarnation of Kristine and take the 15th blade in order to make the world back into his Kingdom.