You have become an aspect of the cold, stalking prey to satiate your hunger for time immoral. No need for complexities in the laws of nature. 

You are shrouded by a 15ft radius globe of snow and ice (considered light obscurity) that suffuses your form while you are conscious, which you can suppress the size of; down to as little as a single foot radius. This area counts as if it were the area of a Spirit Guardians spell cast by you, except it does cold damage and is upcast at the highest level of spells you are able to cast. Creatures who drop to 0 hit points within this area can be instead preserved in ice; they are stable, and cannot take damage until the start of their next turn. This effect ends early if the target is not at 0 hit points.