I forgot the name of this novel. The main character is called Lin Ming. He uses guns, and there seems to be a Rubik's cube. There is also a dog called Magic Light.

Answer 1

" Reborn as a Duke in a Foreign World " is a fantasy sword and magic novel written by the author, Fat Otaku Lin. The general plot of this novel is as follows:

Lin Xingchen, whose soul had transmigrated into the Magic World, used his identity as a Duke to launch an industrial revolution in this Magic World. With his unique golden finger, he transformed from the poorest Duke into the richest Duke on the continent.
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" Call of the Whole People: Succubus Becoming a Berserker at the Beginning " was a fantasy novel written by Sleepless This Place. The general plot of this novel was:

Other people summoned behemoths, giant dragons, and battle eagles, but Fang Lin summoned a delicate succubus. Just as Fang Lin was about to walk down the path of a pretty boy with tears in his eyes, he unexpectedly discovered that his succubus could change its class. Rampage, Cross Slash, Rage Burst, Soul-Devouring Blood Hand, Whirlwind Slash…What was that? It was fine if this Succubus was a Berserker, but why did the other one know Holy Light Prayer? Silly girl. Even though she was dressed scantily and smoked and drank alcohol, I knew that she was a good girl. Faced with the complaints of countless Summoners, Fang Lin expressed calmly," It's normal for girls to have a hundred million points of self-defense, alright?" 
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" The Era of the Spear God of Creation " was a gaming and e-sports novel written by the author, Night Cat. The general plot of this novel was:

What was the Spear God?
100% accuracy;
What was the Spear God?
One fatal blow;
What was the Spear God?
Precise positioning;
What was the Spear God?
Lin Lang said,"Killing people and not dying is the spear god."
He wanted to see how Lin Lang would show off his skills in the Gun God Era and eventually become the champion of the competition.
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Super Demon Hunter was a game novel written by the author, Short Crane. The general plot of the novel was:

There were chivalrous swordsmen, ghosts trapped by love, priests who could summon the wind and rain, and monks who were indestructible. There were also firm and pious paladins, greedy goblins, noble and elegant vampires, and powerful and mysterious magicians…When the naked Lin Yi Chen climbed out of the blood pool of the demon world with the game system from his previous life, a new legend began…
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This Demon King Must Die is a light novel written by half of me, an original fantasy novel. The general plot of this novel is:

If there was only one demon king in this world, it would be me, Lin Qi.
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" When I Made the Spear of Arden " was a light novel written by the author, Life Belly Dog. It was an original fantasy novel. The general plot of this novel was:

None of the students from Myriad Spirit Academy knew why Lin An was so happy after summoning a low-level self-disciplined magic puppet. Until many years later, they saw a golden battleship covering the entire sky…
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The book," Lord of Woodside ", was a fantasy sword and magic novel written by the author, still a child. The general plot of the novel was:

He was a despicable gravedigger and the incarnation of the demon king. He was nine feet tall, and there were evil wizards and vampires living in his territory. His knights were like evil spirits, riding skeleton horses on the ground. Wherever his army went, not a blade of grass grew…
…
In the castle, beside the warm fireplace, Grimm stared blankly at the fairy tale book in his hand. He asked the vampire lady who was far away,"Are they really talking about me?"
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" The Legend of the Dark Wizard " was a fantasy-mystery fantasy novel written by Maplefall I of Songdao. The general plot of the novel was:

He was sinister and cunning. He was decisive in killing. His name was Lin Qi. He was a notorious criminal in his previous life. His soul transmigrated into a corpse and became a living dead. He accidentally came into contact with the Sorcerer World and became a wandering Necromancer.
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There's a Monster in My Body was a suspense novel written by the author, Doubtful Ghost. The general plot of the novel was:

A young man named Lin Feng. He possesses extraordinary strength and will bring you to explore this wondrous city…
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" The Demon King Who Traversed Through Time and Space Is Actually a Hero " was a light novel written by the author, Lin Kesong. It was an original fantasy novel. The general plot of this novel was as follows:

Demon King? Hero? My identity doesn't matter. I just want an interesting life.