Planet Theia
Late Heavy Bombardment
Large low-shear-velocity provinces
Great Oxidation
Panspermia
Oxygen Holocaust
Cambrian Explosion
Great Ordiovician Biodiversiation
Planet Theia crashes into proto-Earth, forming the two LLSVPs. They're both sentient and semi-aware of one another. The African LLSVP activates during the LHB, triggering the start of life on earth (maybe life started before LHB and LLSVP just saves it? idk man). Later the Pacific LLSVP activates and causes the Oxygen Crisis, curtailing and standardizing life. African reactivates and causes the Cambrian Explosion, Pacific reactivates later and causes Ordovician thing. They're both trying to reactivate in the present day in response to the Holocene Extinction
Issue: Need to find more events to link to them, but that's also just background fluff. What should the story in the curr day be? I like idea of doing a keter duty style article where it's one of two random offsets, each focusing more on a specific LLSVP.