Weapon (staff), rare, requires attunement
Made of gnarled wood, with three tentacles twisting around its length, this staff continues the imposing look of Miraak's ensemble.
Whenever a creature attunes to the Staff of Miraak, that creature must make a DC 15 Wisdom Saving throw. On a failure, the creature becomes influenced by the spirit of Miraak still tied to the weapon. They must abide by Miraak's commands so long as they remain attuned to it. They do not wish to part with the weapon and do not possess the means to reveal the item is cursed and controlling them. They deem Miraak to be the one, and only, true Dragonborn.
On a success, they are made aware of Miraak's control. So long as they remain attuned to and wield the staff, they must abide by Miraak's decrees but they possess the capability to discard the weapon and unattune from it if they desire.
While attuned to and using the Staff of Miraak, you can use an action to direct each tentacle to attack a creature you can see within 15 feet of you. Each tentacle makes a melee attack roll with a +9 bonus. On a hit, the tentacle deals 1d6 bludgeoning and 1d6 acid damage. If you hit a target with all three tentacles, it must make a DC 15 Constitution saving throw. On a failure, the creature's speed is halved, it has disadvantage on Dexterity saving throws, and it can't use reactions for 1 minute. Moreover, on each of its turns, it can take either an action or a bonus action, but not both. At the end of each of its turns, it can repeat the saving throw, ending the effect on itself on a success.