Light Infantry commander? Bug?

[Norfleet]

I think this is the "reincarnation" feature.

I had a Mictlan slave spring into being with a custom name and magic paths...both of which corresponded with a recently deceased Tien Chi hero.

So what you're seeing is probably a Light Infantry that's a reincarnation of some other recently deceased individual. If he came into being with magic paths, then in his Last life, he was some sort of mage. If you saw nothing interesting about him, then he was probably a regular commander in his Last life.