Sword Art Online - Vol 5 Chapter 3

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.

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.

Time back to 1981…

This year, the famous President Ronald Reagan officially took office as President of the United States…

This year, the world’s first personal computer officially appeared, and the era of Internet technology officially kicked off…

This year, the ten-year stock market crash has once again come to Hong Kong, the future Asian financial center, and an international metropolis alongside New York and London…

This year, the Cold War continued, the contest between the world’s two superpowers, the polar bear and the bald eagle, still has no winner, and peace is still far away…

This is the best and worst era…

It was also this year that he came…

- Description from novelbuddy