Mashou no Nie 2

A new Demon Kings rises and prepares a huge war against humans. His advances are stopped by humans heroism. The devil kidnaps a shrine maiden who can seal enormous magical power to use her as a trump card for the final battle. The party of adventurers defeats the devil, but leader hesitates to penetrate the enemy, and devil possesses hero's body. No one could imagine that demon forces counter-attack would start with the triumphal return of the adventurer party...

[From vndbreview]