This mysterious piece of alien technology appears nothing characters would normally be familiar with. Characters must figure out how to operate it using the rules in the DMG. Follow the rules for figuring out alien technology.
Device operates on type C power cells.
On a hit the target makes a con save DC 14. On a failed save the victim is effected by stasis and is immediately restrained. On the next round the victim makes a second save. On a failure the victim is petrified. This petrification is caused by encasing the victim in a stasis field.
Once effected by stasis a creature and all of it’s belongings appear to be encased in a mirror like sheen. Creatures in Stasis can not move, do not age, and can not take actions of any kind. Time has stopped for them.
The effect can be ended by dispel magic.
The stasis gun is essentially a basilisk gun. It only effects one creature at a time in any round. Seems pretty powerful. Anyone trapped in stasis could not be effect outside forces and is trapped along with all of their possessions.
Might be good if there were a fumble or wild effect to make the weapon a little unpredictable.