Only I Am The Death Lord

In a Gangster World, A youth was bullied until he was thinking of suicide, but suddenly he saw a blue panel coming to life.
[Ding!]
[You have acquired the Ultimate Gangster System!]
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In an Apocalyptic World, a husband who couldn't even afford to give his daughter a toy for her birthday was staring blankly at the door that was barely holding against the zombies on the other side when he noticed a dark screen come to life.
[Ding!]
[You have acquired the Ultimate Military System!]
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In a Cultivation World, where Hazac is on the verge of death in a quiet wilderness for allegedly offending some 'young master,' he begs God and Demons for a chance to get retribution!
However, someone else heard his prayer![Ding!]
[You have acquired the Ultimate Necromany System!]
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Follow Zachery as he travels around Worlds and Realms, bestowing Systems on individuals who could not even dream of being a protagonist! Not because he was kind, but for the ultimate goal of dominance!
Follow as he builds up his own Legion of Death and conquers the whole Omniverse!
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Inspired by: Fantasy Simulator, Astral Apostle, Super Necromancer System, etc.

So, if you see anything similar to the novel you have read, don't hate my novel, please...

The real story starts in Chapter 14, so you can skip it if you want, but it would make the story less interesting.
I recommend you push through these 14 chapters for proper context and fun reading.