Saw this one story where the guy got "a shard of a cheat system" that only allowed him to isekai for 5 seconds a day to a random world before being isekaied back. Five seconds to snatch Peter Parker's spider and tell him to stay in school, for example. Or five seconds to get beat up when he tries to steal a grandpa-in-a-ring from a xianxia protagonist, because xianxia.