Ultimate Gacha System - Hyoudou Issei

One day, upon waking up from bed after the departure of Irina, Issei was greeted by a screen only he could see. A message explained to him that he received the system known as the Ultimate Gacha System. At first, Issei thought he was dreaming, but he never woke up no matter what he did, whether to slap himself or pinch his arm as painfully as possible. Issei's only explanation was that he was awake. As Issei spun the Gacha wheel, he didn't expect much since 80% of the wheel was filled with trash. However, the message he got from the system shocked him. [Congratulation! The user received (Divine Sword Knowledge – God). The user may access the reward within the Inventory.] However, all this happened when Issei was 10-years-old. Now, he's 17-years-old, seven years after the Ultimate Gacha's arrival. Issei has accumulated so many items and power over the years that could propel him to the top of the Supernatural World if he chooses to do so. Warning: Most of the main story may not be understandable without reading the Auxiliary first, unless you've read Jaune Arc: Ultimate Gacha. This is a Multiverse Story. Tags: Highschool DxD, Overpowered, Multiverse, Gacha, Magic, Harem, Action, Adventure, Comedy, System, R-18 Chapters are between 1k - 3k.