Nil is an AI, and Aeva's partner. The folk tale appears to ring true, as her primary mode of operation is purification and destruction.
A necessary evil, LOGO repeats. He explains that as silly as it sounds, balance is key to keeping things intact. It changes from place to place, increases and decreases in complexity, and manifests in different ways in various value sets. Still, the fundamental concept remains in some ways constant. Nil does what she must.
"Purification" and "destruction" are a lot less chaotic than what one might imagine. In reality, "deletion" might be more appropriate. "Existence should not always be indefinite", claims LOGO.