Protector

Starting at the third level when you choose this archetype you gain the following:

Your initial Fighting Style becomes Protection, if not already (When a creature you can see attacks a target other than you that is within 5 feet of you, you can use your reaction to impose disadvantage on the attack roll. You must be wielding a shield.). At level 7, the range increases to 10 feet. At level 17, you may also move 5 feet towards the attacker without providing opportunity attacks.

You gain special reactions. The number of special reactions you have is equal to your Constitution Modifier. Minimum of 2 special reactions. All Special reactions reset after a long rest, 1/2 rounded down regained from a short rest.

You gain the Special reaction "Parry" (when another creature damages you with a melee attack, you can use your reaction to reduce the damage equal to 1d10 + Constitution Modifier.)

You gain the Special reaction "Taunt" (When a creature you can see attacks a target other than you that is within 5 feet of you, you can use your reaction to redirect that attack to yourself instead. You must use the same attack roll outcome.)

You gain the Special reaction "Raise Shield" (when another creature attacks you, you can use your reaction to raise your shield to increase your AC to the amount equal to your proficiency bonus until the end of the current creature/player's turn.)

Improved Reaction

Beginning when you choose this archetype at 3rd level, Gain an additional reaction per round for a total of 2 reactions. Only one reaction is allowed per turn.

Greater Protection

At level 7, Shields provide an additional +1 AC bonus when equipped.

Opportune Strikes

At 10th level, you gain Advantage on opportunity attack rolls. Disengage actions by enemy creatures still provide opportunity attacks. Whenever a creature leaves melee range of you will provide a opportunity attack. 

Superior Reaction

At 15 level, Gain an additional 2 reactions per round for a total of 3 reactions. This feature replaced the improved reaction feature acquired at level 3. Only one reaction is allowed per turn.

Juggernaut

At 18th level, you attain the pinnacle of resilience in battle. You have resistance to all physical attacks. You gain +4 to your Constitution ability score and increase the maximum score to 24 (+7 modifier).