I was reading Xanathar’s Guide, and the Celestial Warlock subclass is able to choose a unicorn for their patron. However, in the Monster Manual, unicorns only have a CR of 5. So that raised the question: What happens if a warlock kills their patron? Are they unable to level up, do they lose their powers. Or is this another one of those things where nobody from the actual D&D lore has ever been dumb enough to actually try, so it’s just up to the DM?