Este punhal paralisante é homebrew equilibrado?

Eu criei um punhal mágico que pode paralisar as pessoas, que eu planejo dar à party quando elas atingirem o 10º nível. Está equilibrado?

Dagger of Paralysis

Weapon (dagger), rare

This is a +2 magical weapon. When you attack a target and hit with that attack, you can expend one charge of this dagger to cause the target to make a Constitution saving throw (DC 18). On a failure, the target is paralysed for 1 minute. The target can repeat the saving throw at the end of it's turn, ending the effect on a success.

This dagger has 3 charges, which reset at dawn. If you use the last charge, you must firstly make a Constitution save (DC 18) or be paralysed for 1 minute. You cannot repeat this save. Secondly, you must roll a d20. On a 1, the dagger is magically transported to a random spot on the material plane.