Altar of Binding

Wondrous item, very rare

This wooden, portable altar bears carvings of winged angelic and demonic creatures in shackles.

When you cast planar ally within 5 feet of this altar, you gain advantage on Charisma (Deception), Charisma (Intimidation), and Charisma (Persuasion) ability checks against the creature you summon. Additionally, any payment requested by that creature for its services is decreased by 50%.