MTL - Super Soldier - Chapter 2479 Turn into a demon?

This is not your usual isekai novel. it has my unique world background, unique power system and i am trying it make it a unique experience for every reader. :)

Athan, a 16-year-old boy, lived until he was killed for a stupid reason. (stupid reason & more in the prologue:v)

But it seems that fate had stored different things for him as after death as he transmigrated in the magical world inside a dead body of a boy with the same name and same facial features as him.

He also found out that a mysterious black whirlpool seemed to be inside him.

Was someone responsible for his transmigration? if so then who? and why? or was it pure coincidence that he got a new chance at life?

King Grey has unrivaled strength, wealth, and prestige in a world governed by martial ability. However, solitude lingers closely behind those with great power. Beneath the glamorous exterior of a powerful king lurks the shell of man, devoid of purpose and will. 

Reincarnated into a new world filled with magic and monsters, the king has a second chance to relive his life. Correcting the mistakes of his past will not be his only challenge, however. Underneath the peace and prosperity of the new world is an undercurrent threatening to destroy everything he has worked for, questioning his role and reason for being born again. 

Ding![QUEST: Defeat the Abyssal Realm Lord. Grimzark, The Dread of Tyrant.]DESCRIPTION: The Abyss Realm was once under the rule of Goddess Zyraena, but it fell into darkness when the Fallen God, Grimzark defeated it's guardian and took control.OBJECTIVE: Reclaim Goddess Zyraena's realm.Reward: Hidden Class, Gold Coins, Experience, Legendary Weapon, Return to Earth ,REUNITE WITH YOUR MOTHER Etc.Time Limit: None.Penalty for Failure: Death.You will be transported to the Abyss Realm in 5..4...3...Han Seojun is frail and barely more than skin and bones from a life of poverty, was raised by his hardworking mother with no knowledge of his father. At 18, he inherits the Ancient Infinite System, a power passed down for generations from Goddess Zyraena, The Former Echidna (Goddess of Monsters).Over five months, the system transforms his weak body and improves their lives. Just as Seojun is about to take his dream veterinary exam, he's suddenly summoned to the Abyss Realm, a brutal world where only the strong survive.After 500 years of Endless battle with his Guardian Cerberus named Huno and Hydra named Silla, Seojun finally reclaim the Realm.Ding![Congratulations Host! You have max your level! LV. 999,999]Ding![You have obtained a Hidden Class: SSS-Rank Abyssal Tamer.][Title Acquired: Lord of the Abyss]Upon returning, 5 years had passed since his dissapearance and finds the world transformed. Dungeons and monsters are rampant, and people now possess skills and classes granted by a system called global system Where Earth transformed A Game into Reality.People granted is known as the Awakeners and Seojun, protected by his Infinite system, rejected the global system. He is classified as a glitch—a Non-Awakened by the Global System but his level just reset to 1.

Waking up as Space Marine from Warhammer 40K is crazy enough but living in the world of Sword and Magic is beyond crazy. MC has no idea how he ends up in a fantasy world similar to D&D but one thing he is certain, he has to survive and find out who took him away from his home.I do not own Warhammer 40k or picture for fanfiction cover. Please enjoy this fanfiction and if you are interested in Warhammer please check youtube or google for lore.