Shield Warrior

The best offense is a good defense. These fighters specialize in using their shields to protect themselves and allies around them, and punish those foolish enough to approach them. 

Shield Master

When you reach 3rd level, you have become adept at using your shield as a melee weapon. Your shield becomes a martial melee weapon that you are proficient with, dealing 1d8 Bludgeoning damage plus your Strength modifier. The shield can also be thrown to a range of 30ft dealing 1d6 Bludgeoning damage plus your strength modifier. Your shield automatically returns to you after the attack, regardless if it succeeds or fails.

Enemies hit with your shield attacks must make a CON saving throw (8 + proficiency bonus + STR modifier) or receive disadvantage on all attack rolls made on creatures other than you.

The damage of these attacks increase to 2d8 and 2d6 at level 15.

Stalwart Soldier

Your defensive training has made you resilient against adversity. At 3rd level, you can add you CON modifier to any STR saving throw, and vice versa (minimum of +1).

Also, you can increase your max HP by 2 at this level, and at each subsequent level.

The Best Defense

At 7th level, you can use your shield to better protect yourself. When hit with an enemy melee or ranged weapon attack, you can use your reaction to take half damage. This action can be used equal to your proficiency bonus, and resets on a short rest.

Hold The Line

At 10th level, you use your shield to protect those around you. As a Bonus Action, you can choose a number of willing allies within 5 ft of to gain a bonus to their AC equal to half your shield AC bonus (rounded down). You can use this action an equal amount of times to 1 plus your CON modifier (minimum of once).

At 18th level, the range increases to 10 ft.

Advancing Guard

At 15th level, you can charge and trample over your enemies. When you move at least 15ft in a straight line, you can force a single target within 5ft of you to make a STR saving throw. On a failed save, the target takes 5d8 force damage, is pushed 15ft in a straight line away from you, and falls prone. On a successful save, the target takes half damage and doesn’t suffer any of the other effects. A target that is at least one size larger than you has advantage on the saving throw. You can use this attack an equal amount of times to your proficiency bonus, and resets on a long rest.

Elite Bastion

At 18th level, your resilience knows no bounds. Your AC now receives a bonus equal to your CON score while you are wearing armor. You also gain a bonus to all proficient skill checks equal to your CON modifier.