Lez works as a guard along with Tei and Wone. She takes her job seriously, but she's still rather easy to strike up a conversation with. At least, moreso than Wone. Tei usually comes to her for advice (often related to Wone) as she's someone who's good at listening.
She's a great soldier but has little interest in becoming an Invader mainly because she doesn't want to be away from her girlfriend for too long. She might come off as rather cold but she's actually pretty clingly and affectionative with her girlfriend.
An Irken Call
Lez has a minor role in An Irken Call, but she serves as the character Tei can rely on. She failed the trial and didn't become an Invader like Wone and Tei, which she's fine with since she's bad at long-distance relationships. Apparently her gf used to be a skilled Invader herself in the past.