Snowstar

Mark is a genius military weapon designer who was kidnapped by a mafia gang after refusing to work for them.
They forced him to design unique weapons for five years, until one day he successfully escaped only to get shot by his trusted comrades.
*Ding! You awakened a weapon system.
When he opened his eyes, he was in a different body and in a different world.
"You want to kill a wild boar without being detected? Forget about bow and arrow. Here, I present you this sniper rifle."
"You want to kill a horde of goblins from the sky? Forget about those flying carpets and brooms. Here, I present you the fighter jet." 
"You want to kill a dragon? Forget about taking the help of the S-class adventure team. Here, I present you a nuclear bomb."
Join Mark Spencer/ Lu Zhen as he brings the whole world to its knees with the help of his weapon system.
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Note: Author isn't born in an English-speaking nation and has no editor either. So, please be understanding if there are any grammatical errors.
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Author's current works: War Online, My Soul card is a Reaper
Author's other notable works:  The Last Slytherin, The Sharingan Hyuga
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You can also support the Author through Patreon

https://www.patreon.com/snowstar

Weapon seller in the world of magic

He's Sui Weisheng, once in a century genius Archer and the future Patriarch of the clan. This thirty-year-old young man is the one that runs the clan behind the scenes.

The Patriarch opened his mouth, "So, um, the reason I summoned you here is… is… is… about… about…"

"Uncle, elite members." The young man leaned his head and slowly whispered in his uncle's ears.

"Ah, yes, three of our Elite members were killed by someone as they were pursuing a criminal. Their life crystals were shattered. And… and… and…" As the Patriarch is stuttering again due to nervousness, his nephew once again whispered something.

He continued, "And the radiance in Elder Hanying's life crystal is dwindling. So, he too was defeated by this same criminal."

The Godly Archer of the Sui clan