Boon of the Heavy Cavalry (5e Epic Boon)
From D&D Wiki
Boon of the Heavy Cavalry
Covered in heavy, glistening armor and atop a majestic steed, you're capable of feats that few will ever achieve.
- While wearing heavy armor, Bludgeoning, Piercing, and Slashing damage you take from weapon attacks is reduced by one-half of your Armor Class (rounded down). This damage reduction does not apply if you are Surprised or while you are Incapacitated.
- While mounted, you can force an attack targeted at your mount to target you instead.
- While mounted and with a shield donned, you can add your shields AC bonus to any Dexterity saving throws your mount makes, using your shield to protect you both.
You must have attained either Heavy Armor Mastery or Shield Mastery before you can gain the Boon of the Heavy Cavalry.