Realist Maou ni Yoru Seiiki Naki Isekai Kaikaku - Vol. 13 Ch. 72

[MangaDex]

 

[Shiden]

Shinsengumi
Old man
Well known enough to be summoned and recognized by the readers

I've played enough FGO to guess that it's Nagakura Shinpachi?

 

[Lightbrand]

Man it'd be a cool subversion to have him go "hmm the mask is enchanted to prevent Toshi from remembering...dispel!"

"Ah! You're xyz"
"Huh what?"

 

[RWorld]

Gatotsu spotted!