Spellbreaker

 

Magic Resistance

Your essence is being cut off from the weave. Beginning when you choose this archetype at 3rd level, you have advantage on saving throws to resist magical effects and conditions. Additionally, healing from spells is halved for you; the other half of the healing magic becomes warped by your disconnection from the weave and is applied as necrotic damage to your first attack on your next turn.

Magic Hunter

In the process of separating yourself from the weave, you have learned a great deal about how spellcasters use it. When you choose this archetype at 3rd level you gain proficiency in the Arcana skill and can use an action sense the pull of recently cast spells and their casters through the weave with a successful Arcana check: 1 minute - DC 6, 1 hour - DC 10, 1 day - DC 14, 1 week - DC 18, 1 month - DC 22, 1 year - DC 26, 1 decade - DC 30. A success grants you the ability to track the pull for 1 hour.

Mage Slayer

Your many encounters with mages have taught you how to better fight them. At 7th level you gain the Mage Slayer feat.

Antimagic Refuge

Starting at 10th level, you can use your reaction to increase your separation from the weave in order to take half damage from a spell; if the spell requires you to make a saving throw, you take no damage on a success and half damage on a failure. You may use this feature a a number of times equal to your proficiency bonus; you regain all expended uses when you finish a long rest.

Spellbreak

At 15th level, you gain the ability to disrupt spells around you. As a bonus action you can force a spell caster within 30 feet to make a concentration check (DC = your Fighter level). If they are not concentrating on a spell, you prevent them from casting any new spells until the end of your next turn unless they succeed on a saving throw using their spellcasting ability (DC = your Fighter level). You can use this feature a number of times equal to your proficiency bonus; you regain all expended uses when you complete a long rest.

Sundered Weave

At 18th level you have achieved complete separation from the weave, creating a void at the center of your being. You can choose to expand this void to create an antimagic field in a 30-foot sphere centered on you for 1 minute. You can do this a number 3 times; you regain all expended uses on a long rest.

You are also now immune to the effects of healing magic, and all healing magic you receive can be converted to necrotic damage added to your next attack.