Oath of the Black Knights

By tradition, paladins are at opposition to necromancy and the undead. Fighting them, in fact, is often a requirement of the class. But there are knights, Black Knights, who use the undead and necromancy in order to uphold the Law rather than see it undone.

Lawful Neutral in alignment, these knights are well-schooled in the necromantic domain of divine magic and the necromancy school of the wizards. The undead, once created, can be used for what ends you deem necessary after all. They aren't required to serve Evil only. 

Most Black Knights serve well enough with the conatraints placed upon them by mortality, but some Black Knights have become mighty liches, though Neutral in alignment, and have fought and destroyed liches representing the forces of Evil.

To be clear, necromancy is frowned upon by any other group of paladins. A Black Knight is seldom welcome anywhere other paladins are found. But there is also an uncomfortable respect given to these warriors who still fight Evil, though by the most unorthodox of means.

TENETS OF THE BLACK KNIGHTS 

Though the end results sought by Black Knights may vary, these tenets bind them together.

Fight Evil. Raising the dead is only permitted if they are used to fight Evil. It is the duty of the Black Knights to stand against Evil.

Do Not Misuse Your Powers. The powers you have come from divine authority and are not to be misused or used casually.

Defend the Poor and Helpless. Evil is defined by disregard for the poor and helpless. Here we draw a clear line dividing us from those who practice Evil.

Destroy Evil When Possible. Wherever it is encountered, Evil should be destroyed. By any means necessary. 

Channel Divinity

When you take this oath at 3rd level, you gain the following two Channel Divinity options.

Enlist Undead. Any undead who are within 30 feet of you must make a Wisdom saving throw or be turned to fight for you for 1 minute after which time they will collapse, no longer animated, if they are still controlled by you. Any undead who are turned to your side may continue to roll Wisdom saving throws to be released from your power and return to their previous actions.

Turn Demons and Devils. You can use your Channel Divinity to voice ancient words that are painful for demons and devils to hear. As an action, you present your holy symbol, and each demon or devil within 30 feet of you that can hear you must make a Wisdom saving throw. On a failed save, the creature is turned for 1 minute or until it takes damage. 

A turned creature must spend its turns trying to move as far away from you as it can, and it can't willingly move to a space within 30 feet of you. It also can't take reactions. For its action, it can only use the Dash action or try to escape from an effect that prevents it from moving. If there's nowhere to move, the creature can use the Dodge action.

If the creature's true form is concealed by an illusion, shape-shifting, or other effect, that form is revealed while it is turned.

Oath Spells

Starting at 3rd level, you have access to the following additional spells.

OATH OF THE BLACK KNIGHTS SPELLS

Paladin Level           Spells    

3rd           False Life, Inflict Wounds

5th          Blindness/Deafness, Silence

9th          Animate Dead, Speak With Dead

13th        Black Tentacles, Blight

17th        Contagion, Raise Dead   

Ward of Vitality

Starting at 7th level, you and any ally within 10 feet of you are immune to necrotic damage. At 18th level, this area of effect becomes 30 feet.

Wraith Form

Starting at 15th level, you are so imbued with power from the undead that you can assume Wraith Form for 1 minute, 3 times per long rest.

While in Wraith Form, you are transparent and blurry to the point where your enemies attack you with disadvantage. You can also evade damage so well that attacks to which there are a saving throw do half damage to you on a failed save and no damage on a successful save.

Lich Form

Starting at 20th level, as a bonus action, once per long rest, you can assume Lich Form and remain a lich until your hit points are reduced to 0, or until you choose to resume your natural form. 

You will use the stat block for a lich from the 5e Monster Manual including it's ability scores. You will have 135 hit points and an Armor Class of 17. You can use all of the spells and attacks available to a lich. 

You can't be killed while in Lich Form. Rather, if your hit points are reduced to 0, you revert to your natural form. Any overkill on hit points that reduced your lich form to 0 is deducted from your natural hit points after you regain your form. You may also resume your natural form anytime you desire but you can't take Lich Form again until a long rest is taken.