Ah, the building of a great rivalry:
She thinks she's finished him off, but Ace emerges in his crimefighting costume to stop her from doing any more damage. She gets away, and Ace can't disarm the bomb, so he takes it inside the bunker and lets it explode. Ace only suffers a slight shock while no one else is affected, since the walls absorbed most of the shockwaves. As for the riddle Ace used on Faceless, he managed to stump both Vega and Cosmo.