Anders's Deathly Shroud

You weave necromantic energy around yourself as a safeguard against the undead. For the duration, undead with an Intelligence of 7 or lower cannot attack you or target you with a spell, and they treat you as an ally. This effect ends on a creature if you deal damage to it.

Intelligent undead are more difficult to shield yourself from with this spell. Undead with an Intelligence of 8 or higher must make a Wisdom saving throw when they see you, becoming charmed by you on a failure. While charmed in this way, a creature is unable to target you with an attack or a spell and regards you as an ally. If you or one of your allies deals damage to the target or forces it to make a saving throw, it may repeat its saving throw against this spell, ending the effect and becoming immune to this spell for 24 hours on a success. If the creature ends the effect by succeeding on its saving throw, it knows it was charmed by you.