The sentence I'm trying to write in English:
There even is a second imperfect within the subjunctive mode, but it's a bit archaic and mostly used in literary contexts.
The verb of interest here is written in bold. Here's my attempt at the sentence in Spanish.
Hay hasta un imperfecto segunda dentro de subjuntivo modo, pero es un poco arcaico y es se usaba principalmente en contextos literarios.
I'm thinking imperfect because in English, the verb is in the past tense, and it is describing a habitual act (kinda). As in, this isn't some specific thing that happened, but a thing that happens. It's not really habitual, but I couldn't think of a better conjugation. I'm thinking passive reflexive, because it isn't used, but being used. Not sure if I've grasped the passive reflexive properly though.