Blood Armour

When you strike a foe with a melee weapon attack, you can immediately cast blood armour as a bonus action. The foe you struck must contain blood; targets that don't bleed don't satisfy the requirement for blood armour. The blood flowing from your foe magically increases in volume and forms a suit of armour around you, granting you armor class 14 + your Dexterity modifier (max of +4) for the spell’s duration. Blood armor has no Strength requirement, doesn't hinder spellcasting, and doesn't incur disadvantage on Dexterity (Stealth) checks. If the creature you struck was celestial, blood armour also grants you advantage on Charisma saving throws.