Isekai Maou to Shoukan Shoujo no Dorei Majutsu Ω

Synopsis

Lumachina is separated from the others and sentenced to execution. Diablo orders the others not to escape because Lumachina asked them not to. Horn inadvertently activates a Holy Grail she took from Diablo's dungeon and a tiny fairy-like girl named Babylon appears. She explains she appears to those who offer blood to the Grail and an embarrassed Horn remembers urinating in it and decides not to tell her. Babylon offers to make Horn stronger, but her spell doesn't work. With little options, Horn puts on the collar. Babylon helps instruct her on her new powers like bewitching men to fall in love with her as they infiltrate the floating church. Just as she reaches the group's cell, a Paladin attacks and injures her. Enraged, Diablo breaks down the door. Horn is disappointed that they could have escaped on their own and so she tied her life to Diablo's for nothing, but Diablo thanks her for snapping him out of his foolishness in obeying Lumachina, as he is a Demon Lord and obeys no one. He gives Horn a healing potion, then defeats the Paladin after a little difficulty. Diablo flies outside and bombards the church with lightning while demanding Lumachina. When she is presented by guards, he sentences the worshipers to death; his plan being that Lumachina will rebuke him to save them and then he will pretend to fall to make Lumachina a hero. His plan goes awry when Lumachina agrees with "God" to smite everyone, believing the worthy will go to Heaven. Suddenly, Vishos unleashes a giant monster called Europa.

(Source: Wikipedia)