Skeleton Knight, in Another World - Chapter 15Volume 4 -

Xu Yangyi, an 18-year-old high school student, for the reason that his older twin sister eloped with her girlfriend on the wedding day, was forced to be the surrogate bride by his own father. As a result, he became the wife of the man who should have been his brother-in-law.“You’ve gotta look at me carefully. I’m a man.” Xu Yangyi glared at He Jingyan, who was still getting fresh with him though he already knew Xu Yangyi was indeed a man.“Man?” He Jingyan fiddled with Xu Yangyi’s face with his big hand and gave him a sly smile, “You look identical with your sister, so it doesn’t matter!”

A continuation from where High School DxD Volume 25 left off.

During his patrol, Ji Xiu Yun, a marshal of the Empire, was ambushed and went missing. When he returned, there was a pure white creature crouching on his army cap.

Through genetic testing, it was determined that this cute and delicate little fellow was a creature that had faded away with the mother planet of humans 2000 years ago——a cat.

The last cat in the universe!

The people of the Empire were frenzied!

- Description from Novelupdates

Flatten the Devil's Palace, eradicate the demonic cult, slaughter the demon lairs, sweep through the demon realm, dominate the heavens and earth, control the three realms, be the supreme master of the mysterious sect, master of the Nine Yin, the 17th head of the North Star Sword Sect, the Heavenly Fiend Lone Star, the Supreme Sword Soul, the Supreme Infinite Mysterious Heavenly Wishful Great Sword Patriarch... Also known as Iron Egg, known for the wild history of relentless killing.