One day, Saitama and Genos encounter a creature who can summon black holes. In its last breath following its defeat, it sends Saitama and Genos into a black hole. Thanks to Saitama's punch, they are instead transported to another world. One where everyone has a power, and is pretty much an asshole. At least he has hair again. One-Shot, crossover with uru-chan's "unORDINARY"

One-shot Ninja Slayer/One-Punch Man crossover. It's Ninja Slayer vs Speed o' Sound Sonic!