Blood Armor

When you strike a foe with a melee weapon attack, you can immediately cast Blood Armor as a bonus action. The foe who 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 Armor Class of 18 + your Dexterity modifier for the spell's 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 advantage on charisma saving throws for the duration of the spell.