Invested Champion
If you become the champion of another creature, you gain advantage on all attack rolls against creatures that have attacked your charge within the last round. If you are wielding a shield, and a creature within 5 feet of you attacks your charge, you can use your reaction to impose disadvantage on the attack roll, as if you had the Protection fighting style. If you already have the Protection fighting style, then in addition to imposing disadvantage, you can also push an enemy 5 feet in any direction away from your charge when you take your reaction. You can use a bonus action on your turn to reroll the damage for any successful attack against a creature that is threatening your charge.
Whichever version of the spell is cast, if the distance between the champion and its designated ally increases to more than 60 feet, the spell ends.