Juggernaut

Heavy armor is the juggernaut's best friend.  These fighters familiarize themselves with it to a degree unseen in their peers.

Armor Adept

When you take the Juggernaut option you become exceptionally familiar with heavy armor, granting you +1 to your armor class.  This feature stacks with the Armored fighting style for a total of +2 to your armor class if you took that fighting style.

Sturdy Body

As a result of your training, at 3rd level you gain hit points equal to 2 times your fighter levels.  Each time you level up you gain a further 2 hit points on top of your roll.

Rooted

At 7th level, while you are wearing heavy armor you cannot be displaced from the space you occupy but force, you can still willingly move.  If you fail a save and that failure would cause you to move any distance you instead stay still but otherwise receive full damage.  You cannot use the Evasion feature after gaining this feature.

Crushing charge

On your turn, once per turn, you may use the dash action to charge at a target within to dash range.  If you move at least 10 more feet than your walk speed you make a melee attack roll against the target.  Upon a hit add your armor class to the damage roll and choose whether to knock the target 15 feet back or prone 5 feet in front of you.  Upon a miss all attack rolls against you have advantage until the start of your next turn.

At 20th level you add twice your armor class to the damage roll and ignore resistance in regard to damage based on your armor.

Immovable object

At 15th level, whenever your speed is reduced to 0 you gain +5 to your armor class (as though in 3/4 cover) until your speed increases back to a minimum of 5 feet.  Becoming immobile due to incumbrance does not activated this feature.

Once per long rest you may use your reaction to reduce your speed to 0 until the end of your next turn.

Unyielding

Starting at 18th level, you gain temporary hit points equal to 3 times your armor class at the start of each day after donning your armor.  These hit points are only used when the damage is of the piercing, slashing, or bludgeoning types.