megaera & crowley.
I don't see the worst of humanity, only the gray parts. Tis and Alecto tend to visit humans together, and always at the worst of it. Passionate murders are....common. Thus, they don't really learn to see beyond it. That and Tis has more of the blood than any of us, I doubt she'd ever learn she's capable of it.
What about dog shaped creatures? I doubt he'll let you pet him, as only Zagreus is really capable of it, but Cerberus tends to accept those of us who dwell Below.