In The Light of The Moon

The Great Heart Tree.

A very large, rainbow leaved tree that is the thing the Heartcatch Precure are sworn to protect. Its power is tied to the hearts of people and the Precure's ability to safeguard them. Initially echoed, it will appear at a fountain by a casino on the mountain in Vegas, as discussed previously with Kira. Lily will have felt the echo, but not known quite what it was, and will not discover this until sometime in January.

The Heart Tree is technically an entity, and can react to a Precure's wishes as it once did to restore Yuri's powers upon her begging it to, but that's generally as far as it goes there.

It echoes back with no real power besides a feeling of purity in its presence, however...