The Strongest Steward of the Myriad Worlds

Pai Luosi transmigrates to the Nasuverse, becoming Illya's sworn older brother and the adopted son of Irisviel and Kiritsugu Emiya.

When the Holy Grail War breaks out, Illya wants to go traveling, and that awakens a System.

“Ding! The Plot Choice System is now bound. Host, please make your choice!”

“1: Refuse Illya's request. Reward: the title of Cold-Faced Butler, and Illya's hatred!”

“2: Take her traveling. Reward: the title of Gentle Butler, and Illya's resentment!”

“3: Take her to Fuyuki City. Reward: one random ability card!”

“Wait, that's an option? I choose three!”

“Ding! Congratulations, Host. Your choice was successful. You have received…”

Pai Luosi had thought this was just the Nasuverse. But after bringing Illya to Fuyuki City, he suddenly realized that the world had a very different vibe!

Umaru Doma, Kotoko Iwanaga, Sogo Tokiwa, Toru's human form, and S.H.I.E.L.D.…

This world has some serious problems!