Oath of Protection

The paladin’s tools of war lay bare their motivations. Clenched in one hand is the weapon, a deadly device for exacting righteous judgment. Locked in the other hand is the shield, a symbolic and literal barrier protecting good from evil. Stalwart and steadfast, these protectors are ardent defenders of the Light and all that it touches, and are rejuvenated by its radiance in return. So dedicated they are to their cause that they consecrate the very ground upon which they battle corruption

Avenger's Shield

Starting at 3rd level, you can conjure forth a magic shield-- Appearing from thin air, or originating from your shield if you have one equipped. You hurl it forth at an opponent within 30 feet. The shield requires a DC 8 + your Paladin Level DEX save to avoid and deals 3d6 damage on a hit. If you roll a 6, it then bounces to another hostile target, but cannot hit the same target multiple times: If there are no valid targets, the shield vanishes.

Challenging Smite

Starting at 7th Level you learn to stir rage in the souls of the infidel and the heretic. When you strike a target with Divine Smite, the target must make a Charisma saving throw of a DC = to your Paladin level + 8. If it fails, it has disadvantage on all attacks made against enemies other than you, and must move towards you on its turn. You may use this ability as many times  as you have Divine Smite available. 

Aura of Protection

Starting at 15th level, you learn to radiate Divine protection, granting your allies a +2 to AC and a +5 to all non-magical damage.

Starting at level 18, your Aura of Devotion radiates off you even more strongly, providing 10 resistance to all non-magical damage to allies within 10 feet.

Blessing of Sacrifice

Starting at 20th level, you have mentally and spiritually prepared yourself to be a martyr for your friends. Once per Long Rest, you mark a target you can see in 30 feet with a radiant shield for a number of rounds equal to your Charisma modifier. You suffer 100% of the damage directed at that target for the duration. If you fall during the duration, you briefly suffer broken faith, and have disadvantage on Death Saves.