Freeze had all of a moment to try and swap batteries when the others fell back and others came forward. He was nowhere as fast as the ninjas but a flick of the thumb [u]can[/u] be done in the time it took them to close the distance. The anti-battery detonated just as the three closed in on him, flash freezing the world around them all in a ten foot radius. 

Without focus, the blast was not nearly the same as from his gun, there was no ice walls thick enough to stop bullets. In the middle of the desert was perfect pearl that started to crumble apart the moment arrows shattered the shell. The solid nitrogen would not have been enough to outright kill with such an indirect blast, but the sudden temperature drop should be enough to incapacitate the warriors for a few minutes to hours. Depending on training and precautions to take on an arctic opponent.

This now left the scientist time and opportunity to act. He locked his pistol into the output slot, set the latest half-full battery into his belt and lifted up the smallest of unconscious ninjas as a body shield as he approached the archer.