DnD-3.5 hade Handboken för planerna som beskriver några av händelserna i de nio helerna. Du kan "enkelt" döda en av herrarna, ta plats och sedan inte dö. Några citat från boken är nedan.
Från "Manual of the Planes", en 3.5: e bok:
... Bel betrayed the former Lord of the First, Zariel, for his current position. ... While Bel has succeeded where many failed before him, his climb to power seems to be stalled now, since he does not enjoy the support of other Lords of the Nine, except for possibly Asmodeus.
och
... However, in all the time that Asmodeus has ruled from below, no revolt has ever succeeded in replacing the lord of the ninth layer with a different devil, despite a ploy designed by Asmodeus that once allowed his rivals to think he had been dethroned.
Jag vet inte om DnD-5e har en källbok om frågan, så det här är all information jag kan ge dig.