The Oath of the Witch Hunter is taken by a paladin that cannot reconcile with those who toy with the weave to create their own power.  They see this as a disruption of the natural balance between the planes, potentially putting the realm at risk of another cataclysm.  Witch hunters seek out and destroy mages without prejudice.  Any and all magic wielders are guilty, and they realize the irony in using magic in their mission.  Part of every witch hunter's oath is that they will destroy themself when the mission is complete.

Tenets of the Witch Hunter

The tenets of the Oath of the Witch Hunter are immutable and absolute.  Breaking the Oath not only marks the paladin as an oathbreaker, but also makes them a target of their own order.

No mercy for the wicked. Those who meddle with the weave will be brought to a swift end.

Do not hesitate. The weave weakens every moment that witches walk the realm.

No redemption. Witches are guilty of the highest crime, and nothing can save from the fate they've sealed for themselves.

Complete the circle. When the mission is complete, a witch hunter is their own final target.

Channel Divinity

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

Unweave. As an action, you present your holy symbol and speak a nullifying word, using your Channel Divinity. Each creature you choose within 30 feet must make a Wisdom saving throw.  If a creature fails its saving throw, it is nullified for 1 minute or until the effect ends. An affected creature can repeat its saving throw at the end of each of its turns. On a successful save, the effect ends.

A nullified creature is unable to cast spells or use any other abilities that consume spell slots.

Guided Strike. You can use your Channel Divinity to strike with supernatural accuracy.  When you make an attack roll, you can use your Channel Divinity to gain a +10 bonus to the roll.  You make this choice after you see the roll, but before the DM says whether the attack hits or misses.

Oath Spells

You gain oath spells at the paladin levels listed.

Oath of Devotion Spells

PALADIN LEVEL	SPELLS
3rd	faerie fire, hunter's mark
5th	detect thoughts, hold person
9th	counterspell, dispel magic
13th	arcane eye, greater invisibility
17th	greater restoration, legend lore

Aura of Distraction

Starting at 7th level, your presence makes it difficult for spellcasters to maintain their focus.  While you are conscious, each hostile creature that can see or hear you within 10 feet has disadvantage on concentration checks.

At 18th level, the range of this aura increases to 30 feet.

Sight of the Weave

Beginning at 15th level, you are always under the effects of a detect magic spell.

Retribution

At 20th level, you can cause a divine backdraft to ripple through the weave, harming the caster of a magical effect. As an action, you can choose one creature within 30 feet that is concentrating on a spell or other magical effect and force them to make a concentration check against your spell save DC. On a failed check, the target loses concentration on the spell and takes 8d8 psychic damage.

Once a target fails a check against this feature, you can’t use it again until you finish a long rest.