Decompositions originated like any other DM, coalescing over millions of years from cosmic gases and dust. But unlike any other known DMs, Decompositions developed consciousness and intelligence.
Decompositions sentience is not the result of the fusion of the essence of a superhuman being with the planet, as the goddess Gaea fused her own essence with the biosphere of planet Earth. Rather, Decompositions consciousness evolved naturally within the planet itself, apparently through a process similar to that which enables certain stars to achieve consciousness, Decompositions existed within the so-called "Black Galaxy," which is probably actually a dark nebula near or within the Milky Way Galaxy.