Dungeon Harem Made with Elf Slaves

Mars, a young man who was reborn in another world, is traveling with his elf slave, Lilia. His goal is to conquer the world's seven greatest dungeons and obtain the "Tome of Forbidden Magic," which contains powers beyond comprehension. However, he tends to fall behind in his questing because he is busy making love to Lilia...... all day every day. What adventures await them as they take their own sweet time journeying toward their goal?

(Source: Dash X Comics)