Shinwa Densetsu no Eiyuu no Isekaitan - Volume 4, Chapter 5 – The Heavenly Emperor And The Ice Emperor, Part 8

[The 3000th issue of mysterious arrival is about to open! 】

【This is your only chance to redeem yourself! 】

In the global crisis, Wang Teng opens up his unique talent!

SSS-level talent – unequal exchange!

We are not zero yuan purchase!

But we are not equal exchange!

【The exchange is successful! You exchange half a box of instant noodles for endless extraction of SSS-level talents! 】

【The exchange is successful! You exchange a bottle of Sad Crisp Breeze for Douzhuanxingxiao! 】

…

Since then, Wang Teng has opened a new mode of exchange.

- Description from novelbuddy

This novel is also known as Only I Level Up

10 years ago, after “the Gate” that connected the real world with the monster world opened, some of the ordinary, everyday people received the power to hunt monsters within the Gate. They are known as “Hunters”.

However, not all Hunters are powerful. My name is Sung Jin-Woo, an E-rank Hunter. I’m someone who has to risk his life in the lowliest of catacombs, the “World’s Weakest”.

Having no skills whatsoever to display, I barely earned the required money by fighting in low-leveled catacombs… at least until I found a hidden catacomb with the hardest difficulty within the D-rank catacombs!

In the end, as I was accepting death, I suddenly received a strange power, a quest log that only I could see, a secret to leveling up that only I know about! If I trained in accordance with my quests and hunted monsters, my level would rise.

Changing from the weakest Hunter to the strongest S-rank Hunter!

- Description from Novelupdates

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.

The story begins with the last day of Yggdrasil, a popular online game which is being quietly shut down. Our protagonist Momonga decides to stay in his beloved game until the last moment, so waits for the forced logout. Unexpectedly, the server does not shut down and Momonga is stuck in a skeleton avatar in another world. “The powerful Overlord” needs now to discover the new world and face the continuous challenges that arise.