The Volcano Peoples were a Venusian anti-Acceptancer faction. They spent forty thousand years on a project to create a series of volcanic eruptions. This would put large amounts of dust in the atmosphere, reflecting the sun's heat and lowering the rising temperatures. They calculated it would give them another ten thousand years of civilisation.
Nefkhil and Ruribeg were members of the faction, but were killed before the project was triggered. Mrodtikdhil was the commander, and activated the project. This was not only to extend the Venusian's existence, but to destroy the Sou(ou)shi ship. The project succeeded on both counts. (PROSE: Venusian Lullaby)