Uriel was greatly impressed with the fighting prowess Phlox demonstrated on the arena. She moved fast, effectively and made up for her lack of power with the combat techniques she had learned in the army. She defeated her enemies one after the other without showing any signs of being tired, but things quickly changed when she faced the first ascended on the ladder.
Her opponent was fat, not bulky, he just had a protruding belly that somewhat reminded Uriel of Pangeotis' round belly. Being out of shape wasn't that rare, even for hunters, but being fat was an entirely different matter. Once someone acquired a trait, their energy expense became much higher depending on their rank and trait. Uriel himself once passed out because he didn't change his diet after becoming an ascended, so he knew how rare it was to see a fat ascended and he guessed it had to be related to his trait. Unfortunately for phlox, she didn't think things through.