Mistress, I Was Wrong - Chapter 17 (1)

In the end, war couldn’t be extinguished. But, there was a transformation. Even in the heart of a worthless accomplice in murder who was indifferently continuing his task, there was a transformation. The massive weapon “Object”.

This was a weapon that changed the whole definition of war. An exchange student named Quenser, who was dispatched to the battlefield, met at the base a girl with a strange aura. The girl, dubbed “Elite”, is the pilot of “Object”. The near future. This diminutive boy had come to take on the role of standing up against the strongest weapon “Object” for the sake of the girl. This was the motive for their first meeting.

Once I’ve become Immortal, then my attempt to conquer the world shall begin.

I, Zhong Shan, in order establish a supreme heavenly dynasty, must marshal all the luck that I can gather to cleanse my own karma. Then I will have the strength to fight heaven itself, create a new world, and live forever.

First: Fate

Second: Luck

Third: Feng Shui

Four: Cultivate Inner Virtue.

Five: Fame

To gain eternal life.

To obtain fame, one must establish a heavenly dynasty and amass the luck of the world!

To cultivate inner virtue, one must establish holy sites and accumulate an immeasurable amount of merit!

To cultivate Feng Shui one must learn to communicate between yin and yang and control the powers of heaven and earth!

To cultivate luck! To cultivate fate!

Ask the whole world, who can have eternal life!

- Description from Novelupdates

Elena, who spent her entire life as a cold-blooded female knight to avenge her family, ended up dying without claiming her revenge. When she opened her eyes she found that she went back into the past. By day she was a lady in a dress, and at night she carried a sword to change history and prevent her family’s destruction.

God plucked one of his creations from his first Earth and gave him a second chance in another one of his Earths...surprise it is in DxD! Now reincarnated as a perverted side character how will our poor protagonist handle his new identity? Well he probably wont make the choices you will want him to, that's for sure!