Aegis

You channel a layer of energy over your body to protect you from the next attack that hits you. The shield grants you immunity to the next attack that hits you, up to a certain damage threshold equal to 5 times your spellcasting modifier. Upon taking a hit, the shield shatters with excess damage over the threshold being taken as normal. This effect protects against all forms of external attack (including weapons, the fiery breath of a dragon, et cetera) but not to attacks that are not physical by definition (psychic attacks and poison, for example).