oughhhh

Upon checking it, he uses a few different ones! in Thistle's flashback of him saying he's scared of dying, and potentially the scene with him begging thistle to save Eodio, (hard to place if it's coming from him or thistle) he uses 僕(boku) (interestingly, the former is one of the scenes where thistle uses ぼく, the same but in kana...)

However in the cake comic (where he's a child) from the adventurer's bible, he uses 俺(ore)... it's hard to say what he would use in a casual setting with family, since aside from the wedding and the cake comic, I found the only times he refers to himself is in very vulnerable moments... The exact nuance is something I'm still not super familiar with, though. (this is why I myself default to using 僕... very easy pronoun. Slightly masculine and appropriate both for casual and non-formal polite conversation, even if it gives a childish impression... I wonder if this is why Thistle uses it so much?)

Homegrown

Thistle and Delgal - Dungeon Meshi, Ryoko Kui

^ Fernando Pessoa / Killing Flies, Michael Dickman / A Brother Named Gethsemane, Natalie Diaz / Antigonick, Anne Carson v Oats We Sow, Gregory and the Hawk

thistle and the "my cat is sad" poem.