Path of the Iron Giant

While many barbarians pride themselves on their armorless bodies, dismissing those who wear it as puny weaklings too weak to fight without it, some decide to use--and abuse--the thick, bulky suits of metal that can turn even the frailest of men into a living wall. Some warriors utilize steel to amplify their natural resilience to inhuman levels, transforming them into an unyielding menace who simply cannot be harmed. Smaller men can do nothing but stare in awe at the juggernaut before them: an Iron Giant.

Armorclad Anger

When you choose this subclass at 3rd level, you gain proficiency with heavy armor, and can still benefit from raging while wearing it.

Stoic

At 3rd level, incoming attacks simply don't faze you like they used to. After a hostile creature makes an attack roll against you, you gain one Negation Point. Your maximum number of Negation Points equals your Constitution modifier multiplied by two.

Once per round, when a creature makes an attack roll against you, you may expend any amount of Negation Points, and reduce the roll by that amount. You may do this after the roll is made, but before the DM declares a hit.

Any Negation Points you possess are lost after a rest is completed.

Statue of War

At 6th level, your mastery of armor allows you to casually stroll into battle, unburdened with silly worries like "dodging" and "walking to a better position".

If you moved 10 feet or less during your turn, attack rolls against you have disadvantage until the start of your next turn.

No Escape

By 10th level, you have grown terrifyingly adept at restricting the movement of others around you, preventing any feeble attempts of escape.

The Disengage action has no effect against you. In addition, when you make an attack of opportunity, you can replace it with a grapple attempt. You may initiate this grapple even if both of your hands are full, although if it is successful you must free up at least one of your hands to grapple. If using a weapon with the reach property, the target is pulled 5 feet towards you if the grapple attempt was successful. The target cannot attempt to break free until its next turn.

Strength without Numbers

By 14th level, your sheer durability and might allow you to fight massive hordes single-handedly, withstanding the abuse of dozens of blades without issue. When you hit with a melee weapon attack, all hostile creatures within 10 feet of you (besides the one you hit) take damage equal to your Strength moudifier + your current amount of Negation Points. In addition, any non-magical bludgeoning, piercing, and slashing damage you take is reduced by an amount equal to your Constitution modifier. This damage reduction is applied before the resistance granted by raging is.