[TOMT] Searching for MANGA

Hey! I’m trying to remember a manga series I read years ago: • Two male classmates — blonde and black-haired — become immortal and must consume souls to survive. I think the blonde one was questioning life and the black haired one made him immortal. • There’s a girl who’s important; at one point, the blonde boy erases a town or consumes their souls and feels deep guilt but he does so to save the girl or prolong her life. • The series is dark, emotional, supernatural, and I read it as a child — it was in used bookstores/libraries.

Any ideas what this series might be?