Dark Delirium

You can plunge a creature into an illusory realm.
As an action, choose a creature that you can see
within 60 feet of you. It must make a Wisdom
saving throw against your warlock spell save DC.
On a failed save, it is charmed or frightened by
you (your choice) for 1 minute or until your concentration is broken (as if you are
concentrating on a spell). This effect ends early
if the creature takes any damage.
See PHB, pg. 109.