Looked up the top-right one, the original phrase is
人は殺さられば、死ぬ。
Which, indeed, means “If a person is killed, they die”. I listened to the whole scene and it sounds like the character does have something weird going on with his body, which prevents him from dying, and what they are meaning to say is “normal people die if they are killed, but I don’t”.
I’d say to each their own, but it’s also a source of BDD for a lot of women. One specific body type usually being the center of sexual attention creates a fair bit of unnecessary expectations. Same as porn industry in general, be it real or drawn, creates very much comparable problems for men. Please look at real people from time to time, it helps.