Honorifics: Idia

Idia refers to most of the first-year students by their first names with the “-shi” honorific.

Idia generally refers to Ortho by his first name without an honorific, with the one-time exception of a vignette where he calls him, “Ortho-kun.”

(There was an error on JP where Idia once referred to the prefect without an honorific, but this has since been corrected.)

Idia generally refers to the second-year students by their first names and the “-shi” honorific.

There is at least one instance of Idia referring to Jamil as “Jamil-dono,” as well as his usual “Jamil-shi.”

Idia will refer to Riddle as “Riddle-shi,” but also “Instructor Riddle” and “Demon-Instructor Riddle.”

During Glorious Masquerade Idia had two new names for Riddle: “the man who can’t empathize with anyone” and “the man who absolutely can’t empathize with anyone.”

Idia refers to all third-year students as “first-name-shi,” no exceptions (including Muscle-Red-shi).

Bonus: Idia will call himself “nii-chan” when talking to Ortho.

This is particularly interesting because Idia’s oft-repeated phrase, “Leave it to nii-chan,” is a holdover from when Ortho was alive.

“Nii-chan” is what dead-Ortho, not Robot-Ortho, calls him, but Idia still repeats the line multiple times to Robot-Ortho.