Actually, he had three undying divine artifacts on him and had activated all of them. The three of them bestowed the Aegis Shield, Reflector, and Armor divine abilities on him. That made six divine artifacts that he was using at the same time.
The reason the remaining two undying divine artifacts failed to do anything was because they were reliant on Aegis Shield to work. Since Aegis failed to block the attack, they couldn't do anything to help Mirlo.
The failure of the defense isn't entirely the fault of the Aegis Shield. The Aegis shield divine ability is powerful, but without enough spiritual energy it couldn't stop four Severs powered by four tentacles strong enough to break a house with raw strength.
This is the fourth advantage of the Blood Limbs. They amplify the attacks with raw physical strength.
