Dark Knight

A Dark Knight is a knight who has taken up arms to serve the downtrodden. They serve no lords or institutions, believing no one is exempt from justice, no matter what their position in society. They protect the commonfolk from not only banditry and wild beasts but from corrupt men who seek to oppress them. In return, Dark Knights are often fed and housed by those they protect, or rely upon bounty hunting and raiding looters to support themselves.

When an adventurer chooses the path of a Dark Knight they understand that they are renouncing their rights to be a regular member of society. They belong to no society, acting as paragons of justice who see no allegiance. To assist them in their quest, Dark Knights are able to sacrifice their own life force to power a well of darkness within themselves. They cause themselves great pain and exhaustion in order to allow dark power to course through their body which they harness in a variety of ways.

Darkside

You fill your weapon with power while increasing your Crimson Rite damage by expending your own blood. When you activate Darkside It activates your crimson rite if it's not active already.

 Additionally, for a number of rounds equal to your Intelligence Modifier, when you make a melee weapon attack while under the effect of Darkside, you deal additional damage of the same type as your Crimson Rite die equal to half your class level. You then lose a number of hit points equal to your level once.

 Uses increase to two at 7th level, to three at 11th, and to four at 15th.

Plunge

Beginning at 3rd level, as an action, you may move to a space beside a creature within a 15ft. radius. You then make a melee weapon attack against that creature, dealing an additional 1d6 damage of the weapon die's type. This damage increases to 2d6 at 6th level, 3d6 at 11th level, and 4d6 at 17th level.

You may use the Plunge feature a number of times equal to your Strength modifier before a long rest.

Will to Resist

You gain proficiency with heavy armor.

Dark Arts

You invoke bursts of power after receiving damage for a limited time.

Every time you receive 20 damage in total you gain one point of Dark Arts to a maximum of 4. As a bonus action, you can spend one point of dark arts and gain additional damage on your melee attacks equal to half your Intelligence modifier rounded down as the same type of your Crimson Rite die when Crimson Rite or Darkside is active. This effect lasts for a number of rounds equal to your Intelligence modifier and it can be used the same amount of times per long rest.

Soul Eater

Beginning at 11th level, once per turn when you make a melee weapon attack, you may choose to recover hit points equal to half the damage dealt by your Crimson Rite or Darkside feature rounded up.

You get a number of uses per long rest equal to your Strength modifier.

Flood of Shadow

As a bonus action and by spending 2 dark arts points, you deal 2d8 psychic damage plus your Darkside and Dark Arts bonus damage if activated, forcing creatures in the line of 30ft with a width of 10ft to make a Dexterity saving throw, if successful they take half damage.

Undying

At 15th level and once per day when you reach 0 hit points, instead of being unconscious, you maintain your posture and stay awake. Everything besides the unconscious status about death saving throws remains the same. Additionally, when you reach 0 hit points, you may use your Reaction and Dark Arts points to do the following.

• 1 Dark Arts point: You may move up to half your movement as a reaction. This move provokes attacks of opportunity.
• 2 Dark Arts points: You may use one action. This action can't be an attack action.
• 3 Dark Arts points: You may use both reactions. 

Edge of Shadow

As a bonus action and by spending 2 dark arts points, you can make an extra weapon attack dealing an extra 3d8 psychic damage plus your Darkside and dark arts bonus damage if activated.

Stalwart Soul

At 18th level and as action, you may unleash the darkness stored within you and deal massive damage to everything around you, even yourself. If Stalwart Soul is used and you're not under the effect of Darkside, you activate Darkside whether you have uses left or not.

Everything but yourself at a 20ft radius from you must make an Intelligence saving throw. If failed, creatures affected take 3d6 psychic damage, plus 3d6 force damage, plus your Darkside damage. Additionally, you may spend 1 Dark Arts point (maximum 3), to create a floating orb of energy inside this area dealing 2d8 plus your Intelligence modifier of force damage. 

You then receive one-third of the total damage besides the damage received by activating Darkside.