MTL - After Rebirth, the Buddha-like Star Is a Medical Expert - Chapter 18 sister said

Long ago a great calamity struck the earth, destroying much of it and merging what remained with pieces of other worlds.

With these worlds came Aether, a new form of energy that can allow one to transcend the bounds of normal mortality and human limitations.

In a world where humans absorb the essence of aether beasts to gain power, Aiden Hawke joins the class of humans known as arcanists, people who defeat aether beasts and absorb their essence into cores they forge within themselves, and who infuse themselves with the aether that permeates the world around them to increase the power of their body and mind.

However, unlike most, Aiden will find that he holds a unique gift and that his journey as an arcanist will not be so simple.

Nyx, Earth's former number one mercenary found himself on the end of his life failing to escape from a powerful criminal mastermind. However, fate seems to have another plan for him when he woke up in a completely different place, a place that he will eventually call home in the new world where strength makes one the biggest boss.[Welcome to the Universal Shop System!][Detected that it is the first-time log-in. Reward: Random Gift Pack (5)][Detected the user entering the Body Tempering Realm. Reward: Infinite Qi System][Opened Random Gift Pack (5). Acquired True Transcendence Body Art (1). Acquired Primordial Nihility Transcendent Qi (1). Acquired Immortal Illusion Art (1). Acquired Grand Desolation Transcendent Body (1). Acquired Extreme Origin Transcendent Soul (1)]With an absurd system as his cheat, follow the young man's journey through the entirety as he gains his position as the one true peerless existence, the sole transcendent above all.

Childhood, upbringing, family background, social relations, traumatic experiences…

We keep reviewing and seeking out the motives of criminals, exploring the subtlest emotions driving them. It’s not to put ourselves in their shoes and sympathize, or even forgive them; it’s not to find some reasons to exculpate their crimes; it’s not to kneel down before the so-called “complexity of human nature”; nor to introspect social conflicts, much less to alienate ourselves into monsters.

We just want to have a fair trial – for ourselves and for those who still have hope for the world.

A seme thug specialized in dealing with various kinds of disobedience vs. a cowardly and dissolute uke descended from a rich family

- 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.