Seiryuu--soon to be called Shin-ah--couldn't have been more surprised when a boy stumbled out of nowhere in the maze-like tunnels of his village; the boy with eyes similar to Ao's, hard and dead, with a glint of cruelty that was probably forced, and, more importantly, a boy that was close to passing out from a fever. Knowing the treatment of outsiders by his people, Seiryuu takes care of the boy himself. The same day the boy, Eren, wakes up, is the day that Yona, the exiled Princess of Kouka, arrives to take Seiryuu away from the darkness to join the other dragons, and Seiryuu refuses to leave Eren at the villagers' mercy.
Eren, for the first time outside the walls that protect humanity from the titans, can't help but see the wonders of Kouka as he travels. But he also sees the cruelty and darkness that Yona is just beginning to see, and accepts her request to join their merry group (despite the protests of Hak and Kija) and aid the people of Kouka.
"I'm a soldier, after all."
Transmigrated into DxD World-Kuoh Town, Hibari Kyoya. an average student, spent 18 agonizing years in the world fully aware of the dangers, knowing he is utterly powerless in a world of gods and monsters, Until...
[Ding! Sign-In System loading... 20%... 50%... 80%... 100%.]
Destiny, it seems.. has a cruel sense of humor. A [Sign-In System], long overdue, finally bursts to life within him, offering a chance at survival, a chance at power...
[Ding! Congratulations! You have received the Rainbow-Grade Gift Bag!]
...
He then started completing System's tasks, accumulating even greater rewards.
[Ding! Task completed. Reward: Perfect Rumble-Rumble Fruit (Weakness to water Removed).]
[Ding! Task completed. Congratulations to the host for obtaining the Flying Thunder God Technique!]