MTL - The Devil’s Cage - Chapter 1820 name

By some ill fortune, Hikaru died in a traffic accident. He was in heaven standing in line, waiting to be judged, when he took an unexpected request to transfer his soul to a person in another world. He received an ability called Soul Board which he could use to allocate points to Skills to make himself more powerful.

But there was a catch…

「I want you to take revenge on someone for me within an hour. If you don’t, I’ll destroy your soul.」

To pull off the task assigned to him, he poured all his available points to the Stealth skill tree.

This is a story of a boy who specialized in Stealth. With his skill trees as weapons, he would demonstrate his unrivaled strength in another world.

After breaking up with his girlfriend, he accidentally acquired a genius system and rose from there against the heavens, becoming invincible..

- Description from Novelupdates

In the 21st century Earth gave Birth to greatest genius ever. A genius who Master myriad of arts. Medicine to Engineering. Mathematics to Micro Biology. Weapon Designing to Environmental control. Music to Painting. Dance to Martial arts. He mastered Everything.

When a person dies, they either die light as a feather (aka unimportant) or heavy as Mt. Tai (aka very important).