Champion tier magic headgear (+1 to MD.) This and other magic items I've created are collected together in the attached PDF.
Twin Circlets of One Mind: A magical pair of circlets worn by an ettin chieftain, allowing the two heads to work in concert with each other, contrary to their normal state of being. They will work for anyone that wears them, but only if both are worn; if only one person equips a circlet, it pretty much just looks weird. While worn, each wearer can hear each others thoughts, allowing them to communicate non-verbally. They can also share recoveries: one can heal using the other's recovery, but only when they would normally be able to on their own turn.
Quirk: Harmony of a Dom and a Sub. When the two wearers disagree on something, they make a d20 roll: whoever rolls higher wins, and both their minds become set on the winner's thoughts.