Aeva is an AI. She has been described as the most proficient creator among the AI, with unparalleled capacity to materialize her will into reality.
Folk legends claim she also created her partner, Nil, as a way of establashing a "cyclical order" in relation to her own motives. Aeva, along with Mora, have gained notoriety among organic lifeforms, as their appearances typically involved acts of "benevolance" towards a group of people.
LOGO claims that the two AI are not to be mistaken for one another. Aeva indeed 'cares' for organic life, but only interferes with their lives by providing them with the many worlds available for exploration. Her more local acts of benevolance are attributed to nothing but pure coincidences.