Talisman of the Sphere
Wondrous item, legendary (requires attunement)
While holding or wearing this talisman, you have Advantage on any Intelligence (Arcana) check you make to control a Sphere of Annihilation. In addition, when you start your turn in control of a Sphere of Annihilation, you can take a Magic action to move it 10 feet plus a number of additional feet equal to 10 times your Intelligence modifier. This movement doesn't have to be in a straight line.
Worth around 200,000 gp, the 2024 value for a legendary wondrous item. How item prices work
Talisman of the Sphere is from the System Reference Document 5.2.1 (“SRD 5.2.1”) by Wizards of the Coast LLC, used under the Creative Commons Attribution 4.0 International License. Full attribution is on the Licenses & Attribution page.