This is the way I understood it:

Based on the flashbacks, there are two types of cells, the Oracle cells, and the types of cells the Oracle cells avoid. Both are a form of Aragami. The avoided cells are some kind of natural divergent evolution of the Oracle cells, protecting themselves naturally from the Oracle cell cycle of consumption.

- The monsters are made of regular Oracle cells.
- God Arcs, the ampules, and the trees are composed of the avoided cells.

Regular Oracle cells feed on anything organic. The avoided cells seem to feed primarily on themselves or on the regular Oracle cells.