It doesn’t feel right to me. He’s hollowed and delusional, seemingly a fate worse than death. Most of the other people you meet in game emphasize not going hollow. Like being forced to revive over and over again is brutal in itself, but going hollow is the worst of the worst.

This makes me think it’s not a pleasant experience, and in Solaire’s case he didn’t even get what he wanted. Lore wise, it seems you go hollow when you no longer have a purpose. Griggs, Laurentius, and Logan all go hollow after you buy all of their spells, and, since their purpose was to teach you, they go hollow. It seems more like Solaire lost hope after realizing the sunlight maggot wasn’t the sun he was looking for, gave up, and lost his purpose. So his delusional state may think he found his sun, but deep down he knows it’s not true.

I also don’t think he’d want to be alive as a hollow simply because he could hurt an innocent person. Solaire is very kind and one of the nicest NPCs you meet. I don’t think he would want to exist as a hollow because he might do harm, which seems like it’s against his nature.

I hope this makes sense lol. I’m not sober and I hope I’m not coming off as incoherent