Rage Meter

The Rage Meter is a mechanic added in Revengeance Mode, along with the Adrenaline Meter. Once the meter has filled up completely, the Rage Mode buff can be activated by pressing the key. The Rage Meter has a minimum value of 0 and a maximum value of 10,000.

Gaining Rage
In order to fill the meter, the player can do any of the following:
 * Get hit by enemies or enemy projectiles.
 * The Rage gained is equivalent to the damage taken by the hit multiplied by 2, with a minimum increase of 1 and a maximum increase of 2500.
 * When using the Profaned Rage Potion, the value is multiplied by 3 instead of 2.
 * This has a one-second cooldown.
 * Hit enemies with True melee strikes, as in a direct hit from a sword or spear and not the projectiles spawned by them.
 * The Rage gained is equivalent to 1/10th of the damage dealt with the hit, with a minimum increase of 1 and a maximum increase of 10 per hit.
 * Rage will only be generated from enemies that have a damage stat of 5 or higher, with the exception of enemies spawned from statues, which will never generate Rage when struck.
 * Wear the Heart of Darkness or Draedon's Heart.
 * The player will gain 0.5 Rage every frame (30 Rage per second) while using the Heart of Darkness, or 1 Rage every frame (60 Rage per second) while using Draedon's Heart.

Rage Mode
When the Rage Mode buff is activated, the player receives a damage boost of +50%. This total damage boost is multiplicative and applied after other damage boosts such as those from Potions or Accessories. Equipping the Heart of Darkness or Draedon's Heart increases the damage boost by 15% regardless of the amount of rage upgrade consumables used.

The player can increase the damage boost by 15% three times to a total of +95% by using these permanent power-up items dropped by defeated bosses:
 * , dropped by Crabulon.
 * , dropped by Ravager.
 * , dropped by The Dragonfolly.

With Adrenaline
When both the Adrenaline Mode and Rage Mode buffs are active at the same time. The player receives a damage boost of +280%. If the player has the Heart of Darkness or Draedon's Heart equipped, the damage boost is +310%.

Using them together ignores all consumable upgrades.

Trivia

 * Rage and Adrenaline are a reference to Ripper Mode from Metal Gear Rising: Revengeance. Because of this, Rage and Adrenaline are often collectively referred to as "Rippers" by the community.
 * Rage and Adrenaline used to have boosted damage increases while in Death Mode.
 * Rage and Adrenaline are replacements for a previous mechanic called Stress.