Seems like this intrudes upon the Death Element's threshold, which should have a lock on poison effects. Maybe if Death Qauntum were used instead.
Also it freezes, sort of. Though, time can semi-freeze "time bubble," as well. Maybe word its effect to say nuero-something.
Or better yet, Make it something venomous and water related, Water for the freeze aspect, Death for the venom. Thus, avoiding figuring out how to have entropy justify a Freezing ability.