Yuuko knows him, the two criminals who attacked them are....
Fuyuki won't finish him off however, he's already exerting a deterrent effect on the two of them.
As great as space and time moves are there must be weaknesses and that's at the speed of activating them at a fraction of a second. Fuyuki can overcome that, he has shown the results of his training so far with Mawaru and Hiyori.
How can't he win? While he had been dealing with Mawaru's acceleration move....
Hiyori did, even if only by relying on teleportation, he wouldn't be able to advance and at least he had already modified some form of his ability.
Although he had never shown his perfect elf form but he felt the results of his training were much better than before.
....
"Now... What are we doing them?" asked Fuyuki who was still with a cold look despite having already deactivated her strength.