MTL - General, You’ve Lost Your Inhibitor! - Chapter 7 student missing

The figure of the Armada seems to be still riding the wind and waves in the Atlantic Ocean, and the gold of South America still seems to flow in continuously. As Alfonso from the Bourbon family returns to the Royal Palace of Madrid where he was born, the story begins here…

- Description from novelbuddy

Returning to the Mysterious Era features a boy who can time-travel back to the past using old relics. The twist? He’s stuck in the body of the relic’s owner.After a near-death experience, Cassius unlocks his ability to travel to the past in the body of Li Wei, a member of the Wind Elephant Sect. Li Wei was a coward who lived a life of regrets up until the day the entire Wind Elephant Sect was mu*dered. As Cassius relives Li Wei’s past, he makes different decisions to show Li Wei a different kind of future.By living out the ups and downs of Li Wei’s life, Cassius is introduced to the world of Covert Martial Arts, ties that run closer than blood, and supernatural forces. Crossing the line between the ordinary and supernatural, he realizes there’s no way back. New friends and enemies slowly integrate into his reality.Now, he must uncover the secrets of Covert Martial Arts and get stronger to survive.

In the era of universal mechas, people can go to the endless abyss, collect materials, strengthen and forge their own mechas, and master the power of destroying the world.

Jiang Chen traveled through time and awakened his talent [Immortal Unarmed]. Once the mecha is broken, he can permanently absorb its power and receive multiple bonuses.

…

At the bottom of the abyss, when the Old Demon God finally broke the Titan mecha with great effort, a hand stretched out from the fragments and held down its head.

“Congratulations, you have unlocked my limiter.”

- Description from novelbuddy

There was a Senior Brother and a Junior Sister. One of them was transmigrated to this world and had cheats while the other was the reincarnation of a Great Emperor.