Fighter: Devoted Defender
The Devoted Defender is a prestige class from Dungeons and Dragons 3.x that I have converted to 5e. It was found it Sword and Fist: A Guidebook to Monks and Fighters
The Devoted Defender is a class where you place your allies safety above your own.
In Harm’s Way: At the start of combat you may choose an ally that you can see. Whenever that ally is within 5 feet of you and is the target of an attack you may use your reaction to switch places with them and become the the target of that attack. You must use this ability before knowing the outcome of the attack.
Saving Grace: Whenever you use In Harm’s Way you may add your Charisma bonus (minimum of 0) to your AC.
I’ve Got This: Whenever you use In Harm’s Way you may also make an attack against the attacking creature.
Charismatic Strike: You may add your Charisma modifier(minimum of 0) to attacks made with I’ve Got This.
I’ll be Your Shield: In Harm’s Way is no longer limited to just a single ally you choose at the beginning of combat, but rather applies to any ally within 5 ft of you.
Devoted Defender: Whenever you use In Harm’s Way and are not hit by the opponents attack it no longer expends the use of your reaction.