Iris is a total failure as a dragon, but I guess it's fine since it works for the story. She only has tiny bits of dragon character, which shows in some minor scenes, like towards the end of this chapter when she randomly kicks a small monster just for the heck of it. But that's about as much dragon arrogance as she has.
@sonyalexandra There was nothing legendary about her. She was the only dragon that didn't have the guts to fight to the death against Gaia (Matthias) back in the ancient history, instead pleading for mercy. She was basically a cowardly dragon, which is why she survived. She's more like a winged dog than a dragon.