The true nature of the beings known as Metron and Mallo are unknown. What is known about both of them is that they each fulfill their personal obligations to reconcile disparative forces in the cosmos. Or put another way, they are keepers of the cosmic balance. And intrinsct in their nature is a curiousity that exceeds the bounds and scope of any other beings in their resepctive dimensions attached to the universes of Earths One and Two. While Metron appeared first, it is evident that Mallo equals him in age and experience.
Metron was a being of similar nature to the residences of New Genesis and Apokolips, though from neither planet. Granted mental attributes which exceeded his own superhuman physique, he created the Mobius Chair powered by an x-element allowing him to travel through space and time. Devising boom tubes for interdimensional transport, he once brought together the Justice Leauge and Society for a mission of salvation towards those of New Genesis. Mallo came equipped with a similar chair, and used his abilities to transfer the powers of Ray Palmer and Al Pratt aka the Atoms of two worlds, stabilizing both realms.