>>95492735Guts is highly emotional so the obvious suggestion would be Lantern Corps.
People might assume he'd immediately become a Red Lantern because rage is his most obvious defining trait, but throughout Black Swordsman and Lost Children the anger was a desperate attempt to cover fear and despair. After determining to
save Casca, I'd say Red or later on even Green might suit him. Especially after donning the Berserker's Armor. But between the Eclipse and Albion, Guts strikes fear and is afraid even more than he is pushed forward by rage. If you pay attention, his veneer of anger cracks pretty often in those arcs, revealing the fear in his eyes.