Death Knight

You choose this subclass when your character is resurrected by an undeath deity or some other dark force that fits the theme of your campaign.
You lose all levels in other classes and gain an equal amount in the fighter class (with DM's approval, you can reallocate your ability scores, proficiencies, and feats).
This subclass is meant to be taken with the Reborn lineage, Warforged race, or any other option that fits the theme of unlife or your campaign.

Dark Arts

When you choose this archetype at 3rd level, you learn to carve Sigils that are fueled by special dice called runic dice.

Runeblade. The only blade a knight of the death will ever need. To access the power of runes, you must first carve them into a worthy weapon (at DM's discretion) over the course of 1 hour, which can be done during a short rest.

Sigils. You learn three sigils of your choice, which are detailed under “Sigils” below. Many sigils enhance an attack in some way. You can use only one sigil per attack.

You learn one additional sigil of your choice at 5th, 7th, 9th, 11th, 13th, and 15th level. Each time you learn a new sigil, you can also replace one sigil you know with a different one.

Runic Dice. You have a number of runic dice (which are d8) equal to your proficiency bonus. A runic die is expended when you use it. You regain all of your expended runic dice when you finish a short rest.

Blood Tap. As a bonus action, you can expend one hit die to regain an expended runic die.

Saving Throws. Some of your sigils require your target to make a saving throw to resist the sigil's effects. The saving throw DC is calculated as follows:

Sigil save DC = 8 + your proficiency bonus + your Strength modifier

Sigils

The sigils are presented in alphabetical order.

Anti-Magic Shell

When you are targeted by a spell or magical effect, you can use your reaction and expend one runic die to attempt to deflect it. Make a Constitution saving throw and add your runic die roll to the total. The DC equals 10 + the spell’s level. On a successful save, you ignore the effect.

Boil Blood

You can use the Attack action and expend one runic die to boil the blood of nearby foes. Each creature within 5 feet of you must make a Constitution saving throw.

A creature takes necrotic damage equal to the runic die roll + Strength modifier on a failed save, or half as much damage on a successful one. A creature is immune to this damage if it has no blood.

Chains of Ice

You can use the Attack action and expend one runic die to restrain a creature of your choice that you can see within 15 feet of you with chains of ice. The target must succeed on a Strength saving throw or take cold damage equal to the roll of the runic die and be restrained until the end of your next turn.

The effect ends for an affected creature if it takes any additional damage.

Corpse Explosion

You can use the Attack action and expend one runic die to make a corpse of your choice that you can see within 30 feet of you explode. Each creature within 10 feet of the corpse must make a Dexterity saving throw. A creature takes necrotic damage equal to the runic die roll + Strength modifier on a failed save, or half as much damage on a successful one.

Dancing Blade

As an action, you can expend a runic die and toss your Runeblade into the air. The blade begins to hover in your space and you can command it to move up to 30 ft. and make an attack. You can't enhance the attack with sigils.

You gain an additional action that can be used only to take the Dash, Disengage, Hide, or Use an Object action. At the end of your turn, the blade flies up to 30 feet and tries to return to your hand. If the blade does not reach you or you have no hand free, it falls to the ground.

Death's Grasp

You can use the Attack action and expend one runic die to create a lash of necrotic energy that strikes at a creature of your choice that you can see within 15 feet of you. The target must succeed on a Strength saving throw or be pulled up to 10 feet in a straight line toward you and then take necrotic damage equal to one roll of runic die if it is within 5 feet of you.

Dominate

As an action, you expend one or more runic dice and speak a one-word command to a creature you can see within 30 feet. The target must succeed on a Wisdom saving throw or follow the command on its next turn. The sigil has no effect if the target can't follow your command, if the command is directly harmful to it, or if the target is immune to the frightened condition.

You can target one additional creature for each runic dice expended after the first.

Heart Strike

When you make a weapon attack roll against a creature, you can expend one runic die to add it to the attack roll. You can use this sigil before or after making the attack roll, but before any effects of the attack are applied.

Leeching Strike

When you hit a creature with a weapon attack, you can expend one runic die to gain temporary hit points equal to the runic die roll + Strength modifier.

Obliterate

When you hit a creature with a weapon attack, you can expend one runic die to attempt to knock the target down. You add the runic die to the attack’s damage roll, and if the target is one size larger than you or smaller, it must make a Strength saving throw. On a failed save, you knock the target prone.

Rune Tap

When a creature hits you with an attack, you can use your reaction and expend one runic die. You add the number you roll on your runic die to your armor class for that attack, potentially causing the attack to miss you.

War Machine

Starting at 7th level, you regain 1 expended runic die each time you roll a 20 on the d20 roll for an attack with your Runeblade or deal a killing blow with your Runeblade to a creature of significant threat (at DM’s discretion).

Improved Runic Dice

At 10th level, your runic dice turn into d10s. At 18th level, they turn into d12s.

Last Stand

Starting at 15th level, you learn how to defy death for a little longer.

When you are reduced to 0 hit points but not killed outright, you regain hit points equal to 1d10 + your Fighter level. You can't use this feature again until you finish a long rest.

Improved Runic Dice

At 18th level, your runic dice turn into d12s.