Legion: Cursed Dominion

"All I wanted was to clear my father's debts, take care of my sister, and then become the strongest hunter in the world but this things inside of me won't let me be."
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Some years ago, portal connecting this world to the other worlds teared open and from it appeared creatures capable of destroying the world.
Miraculously, humans also awakened abilities within them, placing them in a more advantageous situation.
On one of the quests, Benji and his team were faced with defeating higer-ranked creature but it causes them to lose more than they had imagined.
Benji on his part lost significantly as his life was hanging on the line but all of a sudden, hope shines on him. A system.
With the help of the short-term system, Benji is able to level up and become stronger than he was before but along the line, something happens and he is a step away from death's door.
He was expected to die....
Until something awoke in him.
Something from the deepest part of hell.