"These two are complete freaks!", said Nick, now truly not believing that those two could have such strength.
He knew just what kind of power he had used on them, so seeing them escape his ability was a complete shock for him.
His Time Reverse was not only reversing time itself but made sure that anyone affected by its power won't be able to move or do a single thing while he used his power.
No matter if it was an Artifact in the Soul or a Soul Creature until one was affected by his Time Reverse, one shouldn't be able to summon anything or use any power.
However, even like this, Greg was still able to do something which was stated as impossible and escape his power relatively easily.
But what Nick didn't know, that the reason for him to escape was not that his mask's power was strong, but he summoned it right before Nick's ability.