Necross is an incredibly large being that easily dwarfs most of the characters around him. His body is similar to that of a sun inhabitant's and is made primarily of dark rock with glowing magma crags. Necross also has lava pouring out of a crack on the left side of his chest. Necross is a very selfish and cruel creature, as is to be expected from a Guardian that was corrupted into believing the Sun should be his alone. He treats his minions harshly and seems to view them as merely a means to an end. Necross takes great pleasure in casting the world in darkness, appearing to enjoy the Sun's slow death at his hands, and only further reinforced by his amusement at Glim's self-sacrifice in an attempt to reignite the Sun. Both prior to and while in his corrupted state, Necross also acts as a very proud and self-assured individual.