Doom is a Shadow Crystal which is the origin of the beast Night Wandarer.Doom crystal is the most powerful shadow crystal formed by darkness,anger,jealousy,eveything made of negative power.The crystal is shaped like the skull.It has the power to make a light beast into a shadow beast when generated excessive power.It can also absorb power by defeating beasts of any type,whether light or beast.KyoyaBladeX found it along the temple of the old times mentioned in episode3 of the anime series Deploy and Destroy.