'Cause we collect souls. It's, uh... it's complicated.
Far as I can tell, we call ourselves Reapers as a people 'cause we ain't had anything to call ourselves before? No records of there ever bein' anything else, anyhow.

I guess 's like... some families got the name "Carpenter" 'cause they all used to be carpenters, y'know? But if they stopped workin' with wood, they'd still be a "Carpenter", 'cause that's they name.
Even if I stopped collectin' souls, I'd still be a Grim Reaper, 'cause I'm still a part o' Reaperkind.

['Cause that's just the term they use, now!!]