Major post-game spoilers for Legends Arceus but something that stuck out to me is that Volo’s pre-reveal Pokemon is a Togepi that has fully evolved by the time of him going batshit insane. The Togepi line is a friendship evolution. It retains the same gender (female, which only 12.5% of Togepi are) and nature (serious) so it’s definitely the same one, so that means canonically his Togepi/Togekiss adores him. Riolu/Lucario is also friendship evolution, though he could have just caught an already evolved Lucario.
Does this mean he treats his Pokemon a lot better than the title of Pokemon wielder would suggest? Does this mean his Togepi/Togekiss is really gung-ho for genocide? Does this mean his Pokemon is just the world’s worst judge of character? No idea but I find it interesting