The way Arad's traps were was simple. It reflected his lack of experience and harrowing power. He used the threads of the fabric of space to set them, which resulted in powerful yet simple traps.
Nothing would happen if Nyar touched or stepped on the threads, but if Arad pulled on the threads while Nyar was touching them, he could move him alongside the space itself.
But it wasn't easy, Nyar was heavy. Not in the weight sense, in which he was also heavy, but more in the sense that he couldn't be moved against his will. If anyone else touched the threads, Arad would've moved them with ease, but for Nyar, he felt like a poor, sick horse trying to move a fully loaded carriage.
Moving Nyar with the traps in and of itself wasn't harmful, but using that movement to put him in a prime spot to get hit by Vasilissa's attacks was.
Vasilissa smiled from ear to ear. Her son was weak but not useless.
