The Extra is a Genius!? - Chapter 185: Lightning

Wen Er girl is unparalleled in beauty, but when people mention it, she has to sigh because she was born dumb. Unexpectedly, one day, the second girl Wen, who fell from the wall and hit Prince Jing’s body, suddenly spoke.

- Description from novelbuddy

A novel revolving around being transported to another world with an op system. The mc spends his day chasing skirts and doing missions to level up. A standard journey to the top with lots of girls from various animes and games with a twist of that gaming feel (hunting mobs, doing missions).

- Description from novelupdates

As an international mercenary, Feng Luo entered a technologically advanced parallel world during a mission.

After living several years in the new world, an online sci-fi game called War became popular across the entire Star Federation.

Desert Eagles, Barrett, AK-47, Apache, RPG… One after another, familiar gears awakened his memories of the past!

Terminator, Zerg, Resident Evil, the Force,… The missions that appeared after a system update made him even more suspicious and shocked! As such, Feng Luo entered War and became a sniper.

- Description from Novelupdates

This story is set during the end of the Sui Dynasty, a time where multiple powers struggled for supremacy and power.

Into the fray enters two orphans Kou Zhong and Xu Ziling; these two youths by many chances and luck obtain ‘The Secret to Long Life’ allowing the two to obtain profound martial abilities and a chance to rise to the top in this age of turmoil.