MTL - Survivorship Bias - Chapter 156 surrounded by ambush

I, Zatiel, Abyssal Lord, Ruler of Death and Destruction, Nightmare of Dys, have AWOKEN!!!!!.

His life contains events that can shake the universe:
-Fighting against Tiamat, Creator of Evil Dragonkind, in the first circle of hell, while billions of demons and devils butcher each other beneath them
-Start a World War against the Heavenly Race, and transform himself into a Golden Sun while he slaughters their greatest warriors, the Archangel.
-Enter the Final Gate and fight against the Outer Gods.
-Tearing the nine levels of Baator during his battles against the Prince of Evil, Asmodeus.

With his memories as a ruler of the Abyss and a Universal Existence, Zatiel will rise again.

Kieran was just an ordinary part-timer — a high school dropout who had also given up on boxing. With no parents and no real family, he survived by working his ass off every day. He was raised by a man he believed to be his father, but later discovered he wasn't — though the man passed away before the truth could fully sink in. What Kieran didn’t know was that he was actually the sole heir to a powerful business empire, the hidden son of a wealthy tycoon.

Just like how everyone adored heroes in their childhood, a certain young man adored those powers hidden in shadows. After hiding his strength and living the mediocre life of a mob character by day while undergoing frenzied training by night, he finally reincarnates into a different world and gains ultimate power. The young man who is only playing at being a power in the shadows, his misunderstanding subordinates, and a giant organization in the shadows that gets trampled…. This is the story of a young boy who had adored powers in shadows possibly eventually reigning over the world of shadows in another world.

Van and his friend Magus had reincarnated in another world with magic. Tasked to kill the demon lord, they set forth.Van was granted very rough skills that made life for him in that world a living hell, yet he muscled through.Magus however, was bestowed with unfair skills. Due to some of said skills, he gained a harem, which in time, included the girlfriend Van made in the world.After beating the Demon Lord, and after finding out his girlfriend had been stolen from him, he got very upset and so he went to propose to... The Demon Lord...!?