I'm looking for a manga where mc was abandoned by prince for some girl he fell for but it turns out that she was a beauty under the mask and not ugly like he assumed but was also the girl he had fallen in love with as a child , his attempts at apologies fall on deaf ears and she is happy to have gotten herself rid of prince trash. I'm looking for any isekai with characters bringing in guns and equipment against magic or sorcery or barbarian hordes