Another simple, but visually stunning, Grell and Colletta tale in Warlord 23 (July 1979).
This one sees Travis Morgan come to the aid of some peaceful, gold skinned people who are being attacked by green skinned brutes. The golden people, the Children of Ba'al, will not fight to defend either themselves or Morgan, but he finds that they live in total equality, and decides he needs to help them against the green people.
The green people live underground, in a fairly advanced civilization. More advanced than their outward appearance would suggest. Morgan uses his gun to blow up a power source, and then they flee. But when he emerges, the Children of Ba'al knock him out and string him up.
He discovers that they capture and eat the green people, and think that sacrificing Morgan to their god (and presumably then eating him) is the nicest thing they can do. The green people come back and slaughter the Children of Ba'al, and free Morgan. The damage he did to their city was minor, and they enjoyed seeing him realize he had picked the wrong side. But they also make it clear he should move on, and never return.