Shield Brawler

Shield brawlers are generally known to dual wield shields. To most this would seem a waste of a shield as it is more difficult to defend yourself with two shields, but this path shows ways to overcome that downside. 

Weaponized Defense

At 3rd level you may equip two shields with this feature and utilize them as if you were two-weapon fighting. Each shield is considered a light weapon that does 1d6 damage. While holding a shield in both hands you gain a +1 to your AC as your second shield can be partially used for additional defense. If you manage to find +1, +2, or +3 shield, you must choose whether to use the added benefit you your AC or your attack roll and damage roll. You may change your decision when you finish a short rest. 

Immovable Bulwark

At 7th level, when you are subject to an effect that forces you to move, you may use use reaction to steady yourself and resist any effects that force you to move. This can be used even when you fail a saving throw associated with the effect. As a part of this reaction if you are within 5ft of the target who attempted to force your movement, you may make an attack against them.

Improved Defenses

At 10th level, your bonus from having a second shield equipped increases to +2 , and your damage dice increases to 1d8 for your shields. Your shields can also now be used as thrown weapons with a range of 20/60 feet. 

Unstoppable Force, Immovable Object

At 15th level, you manage to find weaknesses in your enemies lines and exploit that weakness. If you move at least 10 feet towards a target and make an attack, the target is immediately shoved 10 feet away from you and are knocked prone. Your movement while using this feature does not provoke opportunity attacks. You may use this feature a number of times equal to your strength modifier (Minimum of once). You regain the ability to use this feature again on a short rest.

Ultimate Phalanx

At 18th level, the damage dice for your shields become 1d10. Your thrown range for your shields also increase to 80/320. When you throw your shield, whether you hit or miss, the shield ricochets back to your hand. Additionally when you have both shields in your hands, you have advantage on saving throws against effects that affect areas (such as a fireball, or a dragons breath). If you save, an area of safety forms behind you in the form of a 45 feet cone.