Anime Crossover: Starting with an Infinite Dragon God As a Mount

He transmigrated to the world of High School DxD and obtained a god-level achievement system. Just as he was considering how to achieve his goal, Orpheus suddenly spoke up. "Let's have a child together." [Ding, congratulations to the host for completing the seven-colored achievement, "Orpheus actively invites you to have a baby!"] [Congratulations to the host for obtaining the achievement reward: Kabbalah Tree!] The Kabbalah Tree, ten primordial elements, four worlds, twenty-two paths, three pillars! Crown, wisdom, understanding, compassion, strictness, beauty... a kingdom! Activity, formation, creation, outflow! "Divine Armor, tenth level! Spiritual reversal, tyrannical ruler!" "This ending, I will never accept, I will never allow! Let it flow into the entire universe, my tyranny, my reason! Let all things restart, eternal return!" "..." Orpheus looked completely innocent: "I just wanted to have a child to defeat the Great Red, why did it turn into..."