Apocalypse: Abnormal Gunslinger

Aberrations, stardust pollution, lack of medical care, lack of food, and unreliable guides, I encountered a lot of troubles right after time travel/awakening. Just escaping from the novice island cost me most of my life. Fortunately, I am immortal now, which is the only good thing. And when the vast apocalyptic wilderness unfolded before our eyes, the survivors respectfully (and somewhat inexplicably) called me "Ephemera", and a new legend began. Yes, I am the immortal mayfly, the famous gunsmith in the wilderness! At the same time, I am also the person who knows how to live a good life. I eliminate aberrations, contain abnormal objects, and search for exotic firearms... The charges are reasonable and no one is cheating! Adapted from the online game "Seven Days in the World"