Disable Helm

You temporarily scramble an operating helm that you can see within range.

This spell drains your life energy to cast, and you suffer 1d8 necrotic damage that cannot be reduced in any way, the helm instantly stops operating and cannot be activated until the spell ends. This damage does not cause you to make a concentration check to maintain this spell. 

The creature attuned to the helm must succeed on a Wisdom saving throw or they are knocked unconscious for 1 minute and take 6d8 psychic damage. On a successful save they take half damage and are not knocked unconscious. If they are knocked unconscious in this way, they cannot be awoken until the spell ends. If the helm is not operating, this spell has no effect.