Spartan

Spartans are the most durable soldiers imaginable. They exist to fight, however they live by a strict code of honor: no solider is superior to another, a calm mind is stronger than a reckless one; and they never, ever, drop their shield. You will fight to your last breath, but you will not put others around you in unnecessary danger. Others look at you and think of you as a brute, but what they do not see is the brilliant tactician that lives within you. You strike with precision without giving the enemy an easy strike against you.

Phalanx

At 3rd level, you have honed your capabilities with a shield. As a bonus action, you can use half your movement speed to raise your shield in front of you, granting yourself half cover from attacks until the start of your next turn. Additionally, assuming you have not moved this turn, you may use an action to spend all of your movement speed to plant yourself in a guarded stance with your shield, granting yourself and any allies within 5ft of you three-quarters cover until the start of your next turn

Riposte

Starting at 7th level, you have mastered the art of deflect-and-counterattack. When a creature within 5 feet of you targets you with a melee attack, you can use your reaction to deflect the incoming attack with your shield. Doing so reduces the incoming damage by 1d12 + the total AC bonus of your shield + your fighter level. If doing do reduces the damage to 0, you may immediately make a melee weapon attack against that creature as part of that same reaction. 

Shield Bash

At 10th level, your experience with your shield has taught you new methods of delivering powerful blows. Whenever you take the Attack action on your turn, you may replace one of your attacks with this ability. When you do so, you thrust your shield into the enemy's face, forcing them to make a con save equal to 8 + Prof + Fighter lvl. On a failed save, the creature is blinded until the end of that creatures next turn.

Victory or Death

Starting at 15th level, you are braver than most; never allowing yourself to retreat from battle. When you fall below half of your maximum hit points, you heal and gain an amount of temporary hit points equal to your fighter level + your proficiency bonus. You also regain one use of second wind. Once per long rest.

Bred for Battle

At 18th level, your expertise in battle has granted you stamina beyond any other warrior. You gain one additional use of your action surge. Additionally, you may now use a two-handed weapon with one hand granted you have a shield in the other hand.