While attuned to an orb, you can use an action to peer into the orb's depths and speak its command word. You must then make a DC 15 Charisma check. On a successful check, you control the orb for as long as you remain attuned to it. On a failed check, you become charmed by the orb for as long as you remain attuned to it.

While you are charmed by the orb, you can't voluntarily end your attunement to it, and the orb casts suggestion on you at will (save DC 18), urging you to work toward the evil ends it desires. The dragon essence within the orb might want many things: the annihilation of a particular people, freedom from the orb, to spread suffering in the world, to advance the worship of Takhisis (Tiamat's name on Krynn), or something else the DM decides.