Obsidian Egg:

The wielder of the Obsidian Egg may choose to dedicate themselves to taking care of the egg once per session. Doing so causes them to lose a health state. Once the Obsidian Egg has absorbed 15 health states, it will hatch. Each time the Obsidian Egg goes a session without absorbing a health state, it will lose 1 HP. If it's HP is reduced to 0, it is destroyed. This loss will not occur if the egg is lost. 10/15 Health States absorbed. 8/10 HP.