Note, though, that Master simply calls him “Inductor” without the -nim, while Danbi adds the -nim. I wasn’t sure about putting the -nim in the actual comic dialogue since it’s not English, and I prefer to not add jargons unless absolutely necessary.
In Korean, it’s completely normal for people to address others by their occupation: e.g. teacher-nim (nim being an honorific thing, kind of like the -san in Japanese), student (an adult addressing a stranger who looks to be school age), “police uncle,” “soldier uncle,” etc. So Danbi calling Lushaka “Inductor” is actually nothing out of ordinary here.