Intercessor

In every battle, there is a front line. A row of death and destruction  where the two sides war for dominance. Intercessors are never more at home than in this struggle. They are the line where their allies rally and the wall upon which enemies break. Those who stand behind them shall know victory, and any who stand against will taste defeat.

Bulwark

When you choose this subclass at level three, you learn to take a nearly unbreakable defensive stance. As an action, you may enter your Bulwark Stance. This stance lasts for a minute or until you take the attack action or cast a spell. When you enter this stance, your movement speed is halved, you gain temporary hit points equal to your fighter level plus your constitution modifier and the AC bonus of your shield is doubled. When the stance ends, you lose any temporary hit points it granted you.  You can activate this ability a number of times equal to your proficiency bonus and regain all expended uses on a short rest. You can only activate this feature if you are wielding a shield

At level 5, you gain temporary hit points equal to 2 times your fighter level plus your constitution modifier. At level 11 this increases to 3 times and at level 20 this increases to 4 times.

Be the Line

Whenever you activate Bulwark, for as long as it is active hostile creatures within 10ft of you have disadvantage on attack rolls made against creatures other than yourself.

Vengeful Guardian

Your mastery of battlefield lockdown has reached new heights. Whenever a creature makes a melee attack against an ally within 15 feet of you you can use your reaction to move into melee range with that creature and make a melee weapon attack. If you hit, the creature cannot attack any creature except you until the end of it's next turn.

Reposition

friendly creatures within 15ft of you cannot be the target of opportunity attacks, additionally as an action while your bulwark is active, you can use your action to command a friendly creature to move up to their movement speed.

Know No Pain, Feel No Fear

You have become the wall at which evil breaks, nothing can get past your guard. You're immune to the frightened condition and cannot be moved, restrained, or knocked prone. While your Bulwark is active you gain resistance to all damage