Mage Slayer

Bane of magic you even the weave with your presence your goal is to kill mages 

Enemy of magic

Your very presence begins to disrupt the weave bending all 

You can no longer cast magic.
You are treated as an enemy for all spells(any buffs or heals from allies must make a spell attack vs (10+con+proficiency)

Add your proficiency bonus to all saves versus spells
Add your proficiency bonus to your AC versus spell attacks

Spell body

Starting at 7th level, you can add half your proficiency bonus (round up) to any Intelligence check you make that doesn’t already use your proficiency bonus

When you see someone cast a spell you can make an Arcana check DC (10 + spell level) to know the level the spell was cast at, its school and its range

Disturb the weave

As a reaction:
If someone casts a spell within 30 ft of you. You can impose disadvantage on the spell attack. Or if an ally within 30 ft of you makes a spell save you can give them advantage

You can use this feature up to you Constitution modifier. Regained on short or long rest

Anti-magic body

All spell attacks made against you are at disadvantage and Advantage on spell saves 

Mage's bane

If you hit with an attack your target must make a save vs 10 + Strength + Proficiency if they fail they lose their highest level spell slot and take a bonus 2x Spell slot level.