I finally checked this back again because of it's rating but just from the chapter alone I can't continue. It's not only because of this specific event of him really doing nothing to warrant the power he was given but also what the way of hyping it up and the grandstanding and what it says about the future of the manga.
Nothing of his sacrifice means anything. His eye is just a little atrophied, his blood is still pumping and he's not disabled or at least paralysed so he still has his whole body. Now along with that, his time isn't really a sacrifice because he was already intending to help, so having them tag along is purely a boon for him not any sacrifice. Also his reactions afterwards basically says the same as my comment, that what he 'gave up' means almost nothing to him because he barely flinched, heck burning him a bit did more to him and they healed that.
Overall the usual ego-stroking isekai and not even the good kind, the pretentious, I'm a saint but badass kind.