The whip caught Hiems off guard. He did not expext her to create a whip, or he didn't expect her to resist at that timing at all. When he felt something wrap around his ankle, he flinched, and stopped attacking. He was already off balance when he realized the girl has used a whip against him.
"Welp."
His tied leg yanked him forward, and though his reflexes tried to resist his lazy mind decided he could accept that failure for a moment(which was not really cool at all). Gravity did its deed and knocked him on his back. Hiems didn't even care to let out a yelp of pain, and instead fell down with his arms spread to the side.
"A NICE TIMED COUNTER FROM YAOYOROZU MOMO! LOOKS LIKE THE TIDE HAS TURNED!"
'Actually this is more comfortable than I thought.' Hiems told to himself as he felt the cool concrete on his back. And of course the pain from the impact. He looked up at Yaoyorozu, ready to spring away when she attacked again.