Kingsoul

Description
''Holy charm symbolising a union between higher beings. The bearer will slowly absorb the limitless SOUL contained within.''

Opens the way to a birthplace.

How to Acquire
After getting both halves, the Kingsoul is automatically created and replaces the slot where the half of the Kingsoul previously resided.

Usefulness
When equipped, the wearer slowly regenerates SOUL at a rate of 2% meter per second.

Kingsoul is a fairly useful charm for exploration and platforming challenges, being superior to Hiveblood in that it can recharge Soul for healing while the player still has full health. However, the high notch cost prevents other useful Charm combinations from being equipped.

This charm is primarily only equipped to unlock the secret area at the bottom of the Abyss, after which it is permanently replaced by Void Heart.

Trivia

 * It is unknown what exactly the "higher beings" referred to in the description are.
 * From the locations the player acquires the halves, it could be inferred that the higher beings are the White Lady and the Pale King, the Pale King being born from a Wyrm and the White Lady appearing to be more of a being of energy rather than a normal bug.