How NOT to Summon a Demon Lord (Manga) Vol. 16

Diablo and his companions arrive at a Dark Elf village, searching for a magic ritual that can extract the soul of the Demon Lord sealed inside of Rem. They succeed in gaining an audience with the village's top-heavy chief, Rafflesia, but there's a problem. Shera is elven royalty, and a deep grudge persists between the elves and dark elves. If Diablo's party is to win Rafflesia's favor, they'll have to fulfill some very tough conditions!