Beat Valkyrie Ixseal

 Present day. Oudou Tsuguhiko, the reincarnation of the Demon King, is an aspiring eroge writer. He lives his life as a human student, all while awaiting the day he can reawaken to his full potential and take over the world. However, when that day finally arrives, he is attacked by Ixseal, a Valkyrie tasked with the mission of claiming the Demon King’s life. Although he manages to escape, he is betrayed by his loyal subordinate, the demon Bezel, who steals all of Tsuguhiko’s dark powers... apart from the power of Lust. With the demons’ plot having left Ixseal stranded on Earth, she joins forces with her former adversary Tsuguhiko in order to fight against Bezel’s demonic army, the Wargrim. To gain enough strength to defeat these powerful demons, Tsuguhiko must use his power of Lust to give Ixseal energy via "dark guidance" (i.e. engaging in sexual activities with her). Will the Demon King and Valkyrie duo seize victory as they learn to fight and live together? Or will they instead meet a most sticky end? VNDB: https://vndb.org/v21142