Dark Knight

A warrior who has embraced the dark in order to gain strength and is willing to sacrifice their own health to defeat their foes. they enhance their damage with necrotic energy, and can choose to sacrifice their own vitality to access new attacks and abilities. in their fervor to defeat their foes, Dark Knights have forsaken shields in favor for greatswords, which they transform into their signature Fellblade.

Darkness

Darkness. you learn two actions of your choice, which are detailed under "Darkness" below. Many action enhance an attack in some way. You can use only one action per attack.

you learn one additional action of your choice at 7th, 10th, and 15th level. Each time you learn a new action, you can also replace one action you know with a different one. you must be attacking with you Fell Blade to use any Darkness actions.

Life Dice. You have four Life Dice, which are d8s. A Life Die is expended when you use it. Unless otherwise stated in the Darkness action, the amount rolled on the Life Die is subtracted from your HP before any effects take place and added to your Life Pool. You regain all of your expended Life Dice when you finish a short or long rest.

You gain another Life Die at 7th level and one more at 15th level.

Damage. Some of your actions add damage to your attacks or do damage by themselves. All damage done from Life Dice or your Life Pool is necrotic.

Life Pool. Some of your actions add life into your Life Pool. This pool is a resource that is used by certain actions and abilities learned at higher levels. If the ;life is subtracted from your HP would incapacitate you, you finish the action and are left with 1 HP, you are made prone, and any remaining Life Dice are lost. On a long rest you Life Pool is reset to 0.

One with Death

At 3rd level, you gain resistance to necrotic damage.

FellBlade

when you chose this archetype at 3rd level, you gain the ability to turn a greatsword into a FellBlade. You spend one hour with your blade, attuning it with necrotic energy, and bonding it to you. This can be done during a short rest. You can only have one FellBlade at any time. If you create another FellBlade, the previous one is destroyed. If the chosen weapon is magical, any effects beyond increase to hit/ damage are lost.

On hit, add 1d4 necrotic damage. Heal half of the necrotic damage done, or all on a critical hit. The 1d4 becomes 1d6 at level 10 and 1d8 at level 18.

the FellBlade's slashing damage counts as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage at level 6 if not already.

All attacks are made at disadvantage if attacking with any melee weapon other than your FellBlade. Ranged attacks are not subject to disadvantage.

Bound Weapon. you can dismiss the weapon as a free action, shunting it to an extradimensional space. As a bonus action, you can call your FellBlade to one of your free hands, at your feet, or in any unoccupied space within 5 feet.

Darkness- Actions

The actions are presented in alphabetical order.

Abyssal Blade

When you hit with a weapon attack, you can choose any amount from your Life Pool and add it to the damage done. Any creature in  a 15ft cube, starting from you takes half of the Life Pool damage. Immediately afterward damage is done roll one Life Die if any remain. Subtract the number rolled from your current HP, this damage is not added to your Life Pool. If you do not have any remaining Life Dice when you make this attack you also take half of the Life Pool damage.

Crushing Blow

When you hit with a weapon attack with the FellBlade, you can expend one Life Die and reduce the enemy's AC by half of the number rolled (rounded up) by a max of 3. The effect last until the start of your next turn.

Dark Bane

When you hit with a weapon attack with the FellBlade, you can expend one Life Die and add the amount rolled to the damage roll.

Infernal Strike

When an enemy triggers an attack opportunity, on a hit roll one Life Die. You can choose to spend any amount from your Life Pool up to the number rolled on the spent Life Die. Add the number to the damage done and reduce the enemy's speed by 5ft per life spent to a minimum of 0

Minus Strike

When you hit with a melee weapon attack you can replace the damage dealt with effects of Minus Strike. You expend one Life Die and you makes a straight DC 12 roll. The targeted enemy takes full damage on a success, or half on a fail. Damage dealt is equal to the difference between your max HP and your current HP.

Sanguine Strike

When you hit with a weapon attack with your FellBlade, you can expend one Life Die. You can choose to add the number rolled as Temp HP or to your Life Pool, but it is not subtracted from your current HP. (Temp HP from multiple Sanguine Strikes can stack, but fade immediately at the end of combat.)

Unholy Sacrifice

Roll 2 Life Dice. All hostile creatures within a 15ft sphere centered on you take damage equal to twice the total rolled. Choose Ally you can see. They gain Temp HP equal to 5 times the number of creatures killed by your Unholy Sacrifice.

Stalwart Behemoth

When you reach 7th level in this class, you gain +1 to Con (MAX 21) and add an additional +2 HP per level after this one.

From the Grave

On a death saving throw, roll 1d8. any hostile creature within 5ft of you takes half damage on a success or full damage on a fail. Roll an additional 2d8 on a critical fail. Do not roll damage if the death saving throw would kill you or stabilize you.

Damage done is necrotic.

Range increases to 10ft at 15th level.

Gloom

When you reach 10th level in this class you can take a bonus action to convert all weapon damage targeting you to necrotic until the end of your next turn

Dark Armor

When you reach 10th level in this class, your affinity with the darkness allows you to extend its's power to your armor, turning it black. you also gain two reaction abilities that can be used once per short rest.
Absorb. Use your reaction to absorb all incoming necrotic damage. one-quarter of the absorbed damage is added to your Life Pool.
Surge. Must have at least 20 points in your Life Pool to use. Expend half of your Life Pool to get advantage on a saving throw or impose disadvantage on an enemy creature's saving throw you can see and is within 60ft of you

Vehemence

(Cannot use while Life or Death is active) As a bonus action you can sacrifice your AC to increase the damage of your next two attacks. The effect last until the start of your next turn. You can use this ability three times per long rest.

Life or Death

(Cannot be used while Vehemence is active) As a bonus action, you can activate Life or Death. Upon activation, increase your AC by 5, ATK by 5,half of your current Life Pool is expended and added to your next attack, the remaining half is expended and added to your Temp HP. Life or Death last until the end of your next turn. Immediately after life or death wears off, make a death saving throw. You take one level of exhaustion on a success. on a fail, reduce your speed to 0 until the end of your next turn, take one level of exhaustion, and the failure from this roll can only be removed by Greater Restoration. The Temp HP from Life or Death last until the end of combat. this ability can only be used once per long rest.