Lifeblood Core

Description
Contains a living core that bleeds precious lifeblood.

When resting, the bearer will gain a coating of lifeblood that protects from a large amount of damage.

The player receives 4 Lifeblood masks which are replenished when resting at a bench. This HP cannot be healed with Focus.

How to Acquire
On the left wall of The Abyss is a cave that will only open if the player has 15 or more Lifeblood masks, either through killing Lifeseeds or through the Lifeblood Heart and Joni's Blessing charms. Joni's Blessing also converts the extra health from Fragile Heart into Lifeblood masks. The charm is found sitting on a dais at the end of the chamber.

There is also an Arcane Egg in the same area. Once the player picks up Lifeblood Core, they will be immediately ejected from the room and the door will become permanently closed, so it is recommended to pick up the Arcane Egg first and then the charm.

Usefulness
As with Lifeblood Heart, this charm is useful if the player has a play style focused on Spells, as it will allow them to use more of their SOUL on casting rather than healing.

Arguably the best Lifeblood charm, as it provides twice as many masks as Lifeblood Heart with only one extra notch cost, and does not turn all masks into Lifeblood unlike Joni's Blessing, allowing for healing if necessary.

However, it is the most difficult to obtain, requiring the player to either collect Lifeblood masks from the Lifeblood Cocoons scattered throughout the area (which will disappear upon resting at a Bench) and/or using the aforementioned Lifeblood charms to unlock the door. The most reliable method is to acquire 7 or more health through collecting Mask Shards, and then equipping Fragile Heart, Lifeblood Heart and Joni's Blessing to reach 15 Lifeblood masks. Then the player still has to reach the door without taking any damage.