Blood Iron Armor

As you cast this spell you take 8 points of damage. Your base AC becomes 15 + your dexterity modifier. The spell ends if you don armor, or if you dismiss the spell as an action. 

When you cast this spell using a spell slot of 3nd level or higher, the spell does 2 extra damage to you and lasts for an additional 2 hours for each level above 2nd.