Path of the Wizard Slayer

The Path of the Wizard slayer is one taken by those who wish to be free of the oppression of magic. Those who go down this path gain resistance to magic but that applies to healing magic and boons such as Blessings. Barbarians who chose this path forgo their resistance to Piercing, Slashing, and Bludgeoning damage in favor of magical damage purely for the intent of spilling the blood of mages.

Arcane Barrier

When you rage, rather than having resistance to Piercing, Bludgeoning, and Slashing damage, instead you have resistance to all damage from Magical sources. This resistance to magic also applies to any beneficial magical effects. Any bonuses from magical effects are cut in half. Examples include but are not limited to potions, healing, inspiration, and blessings. If you roll a die such as Inspiration, you must divide by 2, rounding down (minimum of 1) before applying the effects.

Mage Hunter's Frenzy

Starting when you choose this path at 3rd level, you can go into a frenzy when you rage. In order to do so you must spend 2 rage points, and for the duration of your rage you can make a single melee weapon attack as a bonus action on each of your turns after this one.

Mental Shielding

Beginning at 6th level, you are immune to the charmed and frightened conditions while raging. If you were charmed or frightened before entering your rage, the effect is ends when you rage.

Spellbreaker

Beginning at 10th level, you learn a new technique to nullify spells and magical effects. Whenever you are raging and make a melee attack on your turn, you can immediately use your bonus action to cast the Dispel Magic spell on your target.

Intelligence + proficiency bonus is your spellcasting modifier. 

Spellbane

Starting at 14th level, whenever a spell targets you or an area of effect spell is cast that would affect you, you can use your reaction to cast Counterspell.

Intelligence + proficiency bonus is your spellcasting modifier.