I just met him, wasn't aware he had any activities. I believe it was straight after his "shouting at void and then apologizing for it" dialogue. Tomorrow I'll reload an earlier save and check what happens in detail. If it helps, I'm fairly sure picking up the GLAIVE pauses the puffspam, but it resumes as soon as it's dropped. I could try walking away some distance while it's active to see what happens (it slows down your walking pace a lot as the game is constantly sending dialogue pop-ups.
I'm hoping this CANE might come in handy with the BLOOD SWAMP, because I am not being warmly welcomed lol.