Some Dark Knights give into their anger and rage, and tap into it more than discipline or training. These Dark Breakers go against all the rules of tradition and obliterate with sheer anger.

This is an archetype of Dark Knight

Dark Rage (Ex)

A Dark Breaker can call upon inner reserves of strength and ferocity, granting her additional combat prowess. Starting at 1st level, a Dark Breaker can rage for a number of rounds per day equal to 4 + her Constitution modifier. At each level after 1st, she can rage for 2 additional rounds. Temporary increases to Constitution, such as those gained from spells like dwarf’s endurance, do not increase the total number of rounds that a Dark Breaker can rage per day. A Dark Breaker can enter rage as a free action. The total number of rounds of rage per day is renewed after resting for 8 hours, although these hours do not need to be consecutive.

While in rage, a Dark Breaker gains a +2 bonus on melee attack rolls, melee damage rolls, thrown weapon damage rolls, and Will saving throws against non-emotion effects. In addition, she takes a –2 penalty to Armor Class and Will saves against emotional effects. She also gains 2 temporary hit points per Hit Die. These temporary hit points are lost first when a character takes damage, disappears when the rage ends, and are not replenished if the Dark Breaker enters a rage again within 1 minute of her previous rage. While in rage, a Dark Breaker cannot use any Charisma-, Dexterity-, or Intelligence-based skills (except Acrobatics, Fly, Intimidate, and Ride) or any ability that requires patience or concentration.

At 5th level and every four levels afterward, the maximum bonuses to attack and damage rolls and the maximum penalties to AC and saves all increase by 1, up to a maximum of +6/-6 at 17th level. Each time the dark breaker enters dark rage, he may choose how much, if any, of this additional bonus and penalty he is willing to take on.

A Dark Breaker can end her rage as a free action and is fatigued after rage for a number of rounds equal to 2 times the number of rounds spent in the rage. A Dark Breaker cannot enter a new rage while fatigued or exhausted but can otherwise enter rage multiple times during a single encounter or combat. If a Dark Breaker falls unconscious, her rage immediately ends, placing her in peril of death.
Dark Rage counts as Rage for the purposes of feats and other class features. In addition, if the Dark Breaker stays in rage for more than 3 + his charisma modifier in rounds, he gains the Berserk condition immediately for 1d6 rounds.

This replaces Grimdark Stance and Darkside. Being in Dark Rage counts as being in Darkside for the purposes of using Umbral Arts.

Blood Haze (Su)

While in a Dark Rage, the dark breaker gains a point of Inner Darkness when they successfully hit an opponent with an attack, they may gain up to half their Charisma modifier, minimum 1, points of Inner Darkness per round this way.

In addition, while in Dark Rage, the dark breaker can use Siphon Strike as a swift action, although doing so only lets a single strike recover half the usual amount and successfully landing attacks would not provide Inner Darkness until the start of their next turn.

This modifies Siphon Strike.

Umbral Warrior (Ex/Su)

Dark Breaker treats his total Dark Knight levels as Warrior levels for the purposes of meeting qualifying for Rage talents and feats that have warrior as a prerequisite.
Dark Breakers may take rage techniques (See Warrior for more details on rage techniques) in place of umbral arts. Dark Breakers cannot take Umbral Talents that modify Grimdark stance.

This modifies Umbral Arts

Path of the Breaker (Ex)

The Dark Breaker must take the following path:

Path of the Breaker: The Dark Breaker’s ability to power through with anger shows in their fighting style. The Dark Breaker gains Powerful Maneuvers as a bonus feat, without needing to meet the prerequisites.

At 8th level, the Dark Breaker gains a bonus feat that he meets the prerequisites for, and has Powerful Maneuvers as a prerequisite. In addition, he adds half his bonus to hit from Dark Rage to any Sunder attempts, and half the damage bonus to the damage.

This replaces Path Of The Downtrodden and Improved Path Of The Downtrodden

Group Anger(Ex):

At 14th level, the dark breaker’s anger spills over to his allies. Whenever the dark knight critically hits an enemy creature or uses an Umbral Art or Warrior Talent, allied creatures that can see or hear the Dark Breaker within 30ft gain a +2 morale bonus on damage rolls until the end of the dark knight's next turn.

This replaces Declaration of Blood.

Dreadnought of Rage(Ex)

At 15th level, whenever the dark breaker enters dark rage for the first time in an encounter, he may make a free Intimidate check against all creatures within 15ft of him. In addition, he exudes an aura of destructive might - providing a +4 profane bonus on Sundering checks and damage rolls to allied creatures within 15ft of him.

This modifies Dark Missionary.

Penumbral Obliteration(Su):

At 17th level, the dark breaker’s anger forces a huge force through their strike. Whenever the Dark Breaker gets a critical hit, they can spend two rounds of Dark Rage before rolling to confirm, to reduce the target’s Armor bonus by a number equal to the Dark Breaker’s Charisma modifier.

This replaces Living Dead.