Guardian

Often, when people think of a Fighter, they think of someone in the thick of combat, cutting down their foes with precision and finesse or strength and brutality. Some fighters though, take a different approach to combat, protecting their friends at all costs, risking their life to take hits for them. These fighters, called Guardians by those who see them in combat, tend to leave the flashy combat to the others while ensuring that nobody else is injured. They would rather sacrifice themselves to make sure their companions are safe than let them take a hit when they can prevent it.

Their shield is their tool of choice, never leaving their side. It embodies their ideals of protecting others at all costs, themselves becoming their friends shield. Often seen wielding tower shields, these fighters are often seen using their shield in conjunction with small weapons or even using the shield itself as a weapon. 

Unwavering Defender

Starting at 3rd level, when a friendly creature within 5ft. of you would be targeted by an attack, you can use your reaction to change the target of the attack to yourself, taking the blow for your friend. When targeted by an attack in this manner, you gain temporary resistance to all non-magical damage types. If the former target would have been targeted multiple times as part of a multi-attack, you become the target of all of them, keeping the temporary resistance until the attacks are over.

Shield Adept

Starting at 3rd level, you are able to take up your shield and use it as a weapon, should you so choose. When wielding any shield, you can use it as a weapon. It has the same properties as a warhammer wielded one-handed (1d8 bludgeoning). Once per shortrest, you can use the shield to attempt to stun an opponent. When you make a hit with the shield, your opponent must make a con saving throw equal to (8 + Your proficiency bonus + your strength modifier) or be stunned on a failed save.

Latent Defenses

Starting at the 7th level, you and any friendly creature within 10ft. of you have resistance to bludgeoning, piercing, and slashing from non-magical attacks.

Absolute Defense

Starting at 10th level, when you level up and calculate your HP, your bonus from constitution is doubled.

Mobile Cover

Starting at 15th level, when a friendly creature you can see within 15ft. of you would be the target of an attack, you can choose to move to the creature as a reaction and redirect any attacks that would hit it that turn to yourself as long as you are within 5 feet of it. When done in this way, you have resistance to all bludgeoning, piercing, and slashing from non-magical attacks. You can use this feature 3 times, and uses recharge on a short rest.

Unbreakable Shield

At the 18th level, you have perfected your defense, and have figured out the best way of guarding your friends. When guarding your friends with the Unwavering Defense or Mobile Cover features, you are now able to block any incoming AoE damage that would affect them. The range on Mobile Cover is increased to 30ft, and the resistance granted by those features now gives resistance to all damage, regardless of sources.