You shall carry your sibling, be his support and guide.
He shall be your shelter, guardian, aegis firm.
United you stand, divided you fall.
Thie pearly material is also known by the sinister name of Demon’s Tooth.
“A man needs two things to become a saint. He must perform three miracles, and then he must die. Perform your miracles, sir, and come to me when you are ready to become a saint.”
—Azariah Saintmaker, Dread Lord of Hatred
A cave with weapons sunken into the walls, blades sticking out of the floor and ceiling, and so on. Possibly, any weapon used in it could be torn out of the hand and sink into the stone.