The moment the knife struck towards Victor, he threw his blanket aside and rolled from the couch in a single lightning-fast movement. The weight of his body crushed into Xia's legs, bringing her down. Her back hit the floor with a loud thud, but she didn't drop the knife from her hand. She sat up, going for another stab.
In the pitch black darkness, Xia had an advantage of sight, but Victor had an advantage in everything else. He was simply stronger, faster, better. He was also smart enough to not try to catch or dodge the knife in the dark—instead he threw Xia aside and stood up.
His eyes closed to better concentrate on the other senses. Xia's aura was well-hidden, and she barely made any noise when she stood up, but Victor could hear her thoughts and feel her intentions almost as clearly as if they were his own. If he concentrated, he could see with her eyes, but he knew that'd be more disorienting than not seeing at all.