Extra's Re-awakening: System Errors Made Me Too OP

[A/N: I urge you to give it a try to chapter 20, if you still don't like it then you can drop it, but you won't be disappointed!]
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[Ding! You have defeated the Mobius King Titan!]
[Ding! You have defeated the Primordial Demon General!]
[Ding! You have gained the Dual Soul-Core!]

I was just an average guy with normal dreams, you know? The kind of dreams that teenagers have at one point in their lives. However, I learned the hard way that dreams are completely different from reality.

In the real world, your fate decided your life, and mine was twisted. My father and brother died in an accident, and after attempting to save my mother from her condition, I got hit by a truck.

But death wasn't always the end of one's journey.

Moments after my death, I discovered I awakened the Dragon Sage system and was transmigrating into another world when suddenly, my transmigration was altered by the spell of a goddess whose goal was to summon capable Soul-Hunters.

Because of that, I got transmigrated into the wrong world with two of my classmates. Not as a hero, not even as a low-class villian, but as a no-named character who wasn't even relevant to the story, a character rejected by the author at chapter 2.

An extra.

But hey, in this world where an individual's place in society was decided by their talents, I knew my fate would change now that I had a system, and I awakened a talent too.

But something went wrong.

[Error... Error... Error]

While others awakened talents beyond comprehension, due to an unexpected event, I awakened nothing and was faced with mockery, and eventually, I was abandoned by my teammates.

However, moments before my death, I discovered that because of the goddess's intervention, I awakened something, something no human should have been able to.

[Due to System errors, your false awakening has been deleted.]

[Due to System errors, the hosts Soul-Cores will be reset back to it's default state.]

[Due to system errors, all restrictions has been removed from level 5!]

[Due to system errors, all cooldowns has been temporarily disabled!]

[Rebooting System Functions...]

[System functions has been successful rebooted!]

[Ding! You have fulfilled the conditions for a re-awakening!]

[Ding! You have sealed the shadow contract!]

[Ding! You have obtained a new shadow summoning!]

[Ding! You have tamed the dragon god!]

My system crashed.

And because of it I got access to the infinite powers of the shadows. Now, armed with an army no one man should possess, I took on this world only to discover that my journey wasn't just about becoming the strongest, it was about surviving. So the war against these Soul-Beasts? It wasn't just humanity's fight anymore, it was mine.

I refuse to be at the mercy of fate, so if this world rejected me, I'll reject it too. It made sure of that when it tried to eliminate me.
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[A/N: A bit moderate paced.
Additionally tags: Summons, dragons, extra, weak to strong. Note that the MC has a harsh past, so if you don't like it, this isn't for you.]