There was potential, but I feel like it's being wasted. There's so much that doesn't make sense, from how the main character won't stop acting against his interests (doesn't realize if he's dead now, he's accomplished nothing and betrayed all of his promises), to the heroine just acting like nothing is wrong when her husband is unconscious in the ground and facing the monster that did that. And if she knows what's going to happen, I guess that's different, but then it feels like a deus ex machina.
It's not the worst manga, but there are definitely some poor decisions made in terms of how the story is being told.