Fanatic

Manic Devotion
Beginning at 8th level, your devotion to your god allows you to bask in the truth of their favor and cast aside the paltry crutches upon which the unenlightened rely. The first time each turn you damage an enemy with a weapon attack or spell, you gain one point of Zeal. If you are wearing no armor or cloth armor and are not wielding a shield, you also gain one point of zeal the first time each turn you are damaged by an attack. Additionally, you gain proficiency with the Whip, and may deal 1d4 unresistable slashing damage to yourself as a bonus action while you have a whip equipped and are not wearing medium or heavy armor. Doing so generates one point of zeal. You may store up to five points of zeal at once, and may expend it on the following effects. If no zeal is gained for one minute, you lose all zeal points.
 * Cleanse The Unworthy: When you hit an enemy with an attack using a whip, you may expend zeal to wrack their sinful soul with the scourge of the True God. The attack deals an additional 2d8 necrotic damage if one zeal is spent, and an extra 1d8 necrotic damage for each point of zeal beyond the first.
 * Armor Of Faith: What are the paltry blows of mortal men to one whose flesh welcomes the redeeming kiss of the lash? When you take damage from a spell or weapon attack, you may spend two points of zeal to resist that damage.
 * Scorn The Pretenders: You laugh in the face of the heretics and fools scrabbling for scraps of power, for you have basked in the radiance of divine authority itself. When you make a saving throw against a spell, you may spend three points of zeal to gain Advantage on that saving throw.
 * Undying Zeal: Where other mortals fear death, you stand triumphant even at the gates of the afterlife itself, reveling in the proximity to your god. When you fall to 0HP, you can spend one zeal to remain conscious and continue to act normally. Whenever you would accumulate a failed death saving throw (including from being damaged by an enemy attack), you can spend one zeal to negate it. You cannot gain zeal by any means while at 0HP, and if you accumulate a failed death saving throw without negating it, you immediately fall unconscious and lose all zeal.

Suffer Not The Witch
Beginning at 13th level, your righteous conviction fills you with the swiftness and strength to punish those vile pretenders who would pervert magic against the will of the Most High. You can spend three zeal and use your reaction to make an attack against an enemy within 30' when it casts a spell, disregarding your weapon's usual reach. If this attack hits, the target must make a concentration save against the damage or lose their spell to no effect. Additionally, when you force a creature to make a concentration save using an attack from a whip, that save is made with disadvantage.

One Above All
Beginning at 18th level, such is the strength of your faith that false magics simply melt away in the fires of your conviction. When a creature you are aware of casts a spell, you may spend five zeal points to disbelieve that spell, rewriting fate and causality through sheer conviction. For all purposes, you continue operating as if the spell has never been cast. You may continue acting in a time stop, walk through a conjured stone wall, or emerge from a meteor shower unscathed. Any other creatures still experience the full effects of the spell. After one minute, a spell ignored in this manner reasserts itself in your reality if it is still active.