To become a king and a magician

Natsukawa Tora transmigrated to Type-Moon. He didn't know magic, had no connections, and was busy working odd jobs. He thought he would be the most pathetic transmigrator, but everything changed after he was chosen by the Holy Grail and summoned King Arthur (Old Saber).
Especially after the Holy Grail War ended, and Old Saber became his [Special Space Machine], and he became Old Saber Superman. ...On a certain day of a certain month of a certain year, Chaldea, in that familiar corridor, at that familiar corner.
"Sajyou Aika, don't come any closer! I don't know Arthur well, really! -- Emergency call!"