Fury of the Fallen

Fury of the Fallen is a Charm in Hollow Knight. It increases Nail damage by 75% (rounded to nearest, even when .5) when on 1 mask.

Usefulness
Fury of the Fallen only affects Nail damage, so a build using this charm should be Nail-focused and not Spell-focused.

Since the ability requires the player to be in a near-death state, it is most useful in builds where the player tends to get damaged a lot (being a new or unskilled player) or builds designed to intentionally bring the player down to 1 Mask, such as speedrunning where the player can reliably dodge most attacks.

In a regular game, Fury of the Fallen is only useful if the player is able to avoid taking the last hit of damage for long enough to get in nail hits. Using Quick Slash and Grubberfly's Elegy to deal more damage faster or from a safer distance is recommended. Otherwise, it is more advised to use a charm like Quick Focus to bring the player back into the fight sooner.

While in the Fury of the Fallen state at one HP, gaining extra Lifeblood Masks added onto the end of the HP bar does not negate the effect, making this charm useful for situations such as the Pantheons.

How to Acquire
Found in King's Pass, the starting cavern, behind a spike filled cavern. Look for the Geo cluster in the bottom right of the pit room. Dash to cross the spikes, and continue right to find the charm.

Can be reached at the beginning of the game by nail pogoing on the spikes, or returned to later with the Mothwing Cloak or Mantis Claw.

Trivia

 * Prior to the Lifeblood update, when Fury of the Fallen was activated the screen was bordered with wispy red lines and the Knight was circled in a red icon. Subsequently, the red circle was removed and the effect around the player was changed to be a red smoke.
 * It is useless if all possible hazards and attacks deal two masks of damage (such as when Overcharmed) if the Knight has an even number of masks and has Joni's Blessing or Deep Focus equipped, as this makes it impossible to have an odd number of HP.
 * It is also useless during Radiant bossfights, as it is not possible to reach one mask of health.

Furia de los caídos Ярость павшего Furia Poległych Fureur des disparus