Xia Chuanhu transmigrates to Type-Moon. He can't use magecraft, has no connections, and is busy working odd jobs. He thinks he'll be the most embarrassing transmigrator of all, but everything changes when he's chosen by the Holy Grail and summons King Arthur (Prototype).
Especially after the Holy Grail War ends, Prototype becomes his [special-purpose machine], and he turns into Prototype Superman.
One day, in Chaldea, it's the same familiar hallway and the same familiar corner.
"Sajyou Manaka, don't come any closer! I barely know Arthur, seriously! Emergency call! [What do I do if my friend's ex is hunting me down, Meilin?]"
[My advice is to lie flat and wait for death, dear.]
(This is a revised edition of To Become a King and a Magus. Some plot points in the first two volumes have been changed, and everything from volume three onward is completely different. It'll be free until it surpasses the word count of the previous version. It won't be contracted or put behind a paywall, probably until it reaches around 420,000 words.)
The name is a bit out of place.