Mind Trick

Cast (Action) (Concentration, Up to 8 Hours): You ensorcell a creature that you can see within 12 squares of you. The target makes a Hard (4+) Will test.* A hostile creature has advantage on the test, and a friendly creature has disadvantage on the test. If the target fails, it is charmed by you for the duration (or until you or your companions do anything harmful to it). If the target succeeds, it is immune to your Mind Trick for 24 hours.

While charmed, the target parrots what it hears you say (provided that it can understand you), and it trusts you to the extent that it would trust a friendly acquaintance. At the GM's discretion, a gullible or otherwise weak-minded target trusts you to a greater extent.

When the spell ends, the target learns that you used magic to influence its mind, but -- at your option -- it has no conscious memory of the events that transpired while it was charmed.

You can spend 1 spirit point to heighten *the spell when you cast it, imposing disadvantage on this test.

Mind Trick is far from perfect mind control. Crucially, the meaning of "friendly acquaintance" varies from creature to creature.