You have trained to track down and capture or eliminate those who possess dangerous magical powers.

Witch Hunter Magic

Starting at 3rd level, you learn an additional spell when you reach certain levels in this class, as shown in the Witch Hunter Spells table. The spell counts as a ranger spell for you, but it doesn’t count against the number of ranger spells you know.

Witch Hunter Spells

Weavehound

You track manipulations of the Weave as expertly as a bloodhound tracks a scent.  You can spend a use of your Favored Enemy class feature to cast detect magic without expending a spell slot.  While concentrating on detect magic, if you use the Magic action to spot magical auras and find one on a hostile creature, you can immediately cast hunter's mark on that creature without expending a spell slot.

Disrupting Strikes

Your attacks are particularly disruptive to magic users.

Your hunter's mark deals an additional 1d6 damage (1d10 if you have the Foe Slayer class feature) if the target is concentrating on a spell or magical effect, or if it has used a Magic action since the start of its previous turn.

Additionally, when you use a weapon or unarmed strike to deal damage to a creature concentrating on a spell or magical effect, add your proficiency bonus to the DC of the saving throw the creature must make to maintain concentration.

Spell Deflection

At 7th level, you have learned to defend yourself from spells cast on or at you.

When you are directly targeted by a spell, you may use your reaction either to grant advantage on a saving throw you make to resist the spell, or to impose disadvantage on an attack roll the caster makes to hit you with the spell.  You can use this reaction against spells that target multiple creatures (such as bane or scorching ray), but not against spells that target an area or create an ongoing effect that subsequently targets you (such as flaming sphere or spiritual weapon.)

Evasive Mind

At 11th level, when you're subjected to a spell that allows you to make an Intelligence, Wisdom, or Charisma saving throw to take only half damage, you instead take no damage if you succeed on the saving throw and only half damage if you fail.

Magic Sink

At 15th level, you can cast antimagic field once without expending a spell slot.  You regain the use of this ability when you complete a long rest.