Hydaelyn

You attempt to drain the magic energy from a creature you can see within 30ft. of you to maintain your own magical strength. The target must make a Charisma saving throw; on a failure, they lose a spell slot of first level, and you do not expend your own spell slot. At higher levels, you can drain a spell slot of equal level from the target, but this effect does not work on spell slots higher than 5th level.