[Crossover] Help, Lord Nan Shen!

There's a System inside some idiot's body. Aside from being a vicious smart-mouth while they chat, it can't do anything else. It's completely useless! System: Hmph. But when the System (nanny and guardian) really disappears, something even more terrifying happens! Kudo Naoto QAQ: "Somebody save me!" Saiki Kusuo ^ ^: "Don't worry. I won't use brute force." Deadpan pervert, god-tier seme x Flirty, timid, useless vase uke Worlds to be included, subject to change: Little Shinigami, One-Punching the Sky, Mob Psycho 100, KonoSuba, Twin Souls, and more. Please understand that the original titles can't be used in the blurb. These aren't necessarily the order of transmigration; where they go depends entirely on the author's mood. That's it. *** Release announcement: The novel will go premium on October 29. Please show your support! *** Content warnings: 1. There may be OOC characterization. 2. I'll try to update daily, but I'll give advance notice when I'm busy. 3. The brakes may get slammed on pretty hard later on, so be sure to wear your seat belt. Premise: