It feels kind of goofy to have a series talk about "it's not healing magic! It's medicine!!" and then have the MC wave a staff and heal someone in a blast of light.
No, he does show up previously, but only enough for the existence of a butler to be known, he's the aide that shows MC to the mother's room (and is TL'd as "ludac" in that chap, not "rudac") in chap 3. So we don't get any hints as to motive/etc, but we
do at least see that he exists as an aide prior to his reveal here. I imagine in the LN or WN or whatever this is adapted from, he has a slightly larger speaking role, but here it seems like he's intentionally kept out of panel / in the background to prevent you from thinking too much about him.