The way Volo does care about people despite how he might pretend he hates them and people only ever use and manipulate each other
If he hates the world so much and just wants his suffering to end he could just kill himself or something why are you trying to restart the world so no one ever suffers again, hmm?
Man. I think about what if he won. Would he even have the guts to go through with his plan? He has to. He's come this far. He's done this much. He has to... right?
Him being all friendly wasn't completely an act he really is like that even if he really hated the player and was using them. He likes people. He likes to yap. He likes to gossip. He likes getting all nerdy about ruins. But he's so convinced the world is doomed and beyond saving. So much so he's willing to rip open the sky, manipulate and betray someone who thought of him as a good friend, and take his fight to the heavens and the creator itself.