Blood Armor

When you strike a foe with a melee weapon attack, you can immediately cast BLOOD ARMOR as a bonus action. The foe you struck must contain blood; if the target doesn't bleed, the spell ends without effect. The blood flowing from your foe magically increases in volume and forms a suit of armor around you, granting you an AC of 18+ your Dexterity modifier for the spells duration. This armor has no Strength requirement, doesn't hinder spellcasting, and doesn't incur disadvantage on Dexterity (Stealth) checks. 

If the creature you struck was a celestial, BLOOD ARMOR also grants you advantage on Charisma saving throws for the duration of the spell.