IMPORTANT

On 1.16: Requires Fabric API and Curios API

1.17 and later: Requires Fabric API and Trinkets API

EnderHeart Ender Heart

Craft an Ender Heart by surrounding a Nether Star with 4 Ender Pearls in a crafting table. Ender Hearts are equippable items (they have their own Curios/Trinkets slot!) and can be linked to one another.

EnderSoul Ender Soul

By combining two Ender Hearts with soul sand or soul soil, you create an Ender Soul which links the two hearts together. Using this technique, a single Ender Heart can be linked to as many other Ender Hearts as you want, and as many times as you want.

Teleportation

By using an Ender Soul (right-click while holding it) and wearing one of the Ender Hearts used to create it, you are able to teleport to the player wearing the other Ender Heart that was used to create the soul. This teleportation does not work across dimensions.

Helpful Information:

Name your hearts and souls! This makes it easier to not get confused with which heart links to which player, etc.
Have other "soul" items which you want to use to create souls? Any item contained in the item tag heartbond:soul_crafting_items will work for the Ender Soul recipe!

Heartbond