Which completed novels had an exchange system or the protagonist could upgrade?

While playing an online game, after Luke bought an SSS rank gift card of Superman, he found himself in an unknown yes very familiar Marvel Universe. And with a twist of fate, the SSS rank gift pack has also come with him. After he started to do workout and exercise, he found that the loading screen to unlock the gift card was slowly increasing. However, after reaching 99%, it has stopped moving forward. And when he found the chance to get his hands on the Super Soldier Serum, will he take it? And will it be enough to push the bar till 100%? If no, then how will he survive in one of the most dangerous worlds? If yes, then will he be the Marvel's Superman?

COMPLETED!!!! "Mr Liu Wei.." Liling paused as she took In a deep breath. "I need one million yuan... " Liu Wei shifted his gaze to face her. His face bore a surprised expression. 'What was she using that much money for?' Liling who was anxious held the helm of her gown tightly. She swallowed hard and continued courageously. "I don't think I can pay back..., but I'll give you something else" Her voice drained of all vigour. It was really hard to give herself away, so easily but she had no choice. Taking in a deep breath, she lifted her eyes to look at him. "My body..." ... ‘’Jin Yue, please wait.’’ Jin Yue suddenly stopped in his tracks, he badly wanted to look back but at the end he decided against it. ‘’Speak, I’m in a hurry.’’ ‘’Jin Yue, throug the time we spent together, did you ever, even for a split second, love me?’’ Jin Yue froze when he heard her question. Did he love her? From the moment he set his eyes on her, he had loved her. She had stolen his heart away that even right now, he wanted to kneel and beg her to stay with him. But he wouldn’t tell her that. If he wanted her to stop feeling guilty, he would not tell her. She should hate him so she would be happy with the one she loved. ‘’No; not even for a split second, so Miss Xin Yong, stop being delusional and scrap every memory you have of me.’’ ... This is a story of two couples and the hurdles they meet in their journey of love and how fate tries to bring them back together. I hope you like it.

“As long as I level up another 10 times, I will be able to activate the Gene Lock. At that time, I will be able to destroy this celestial body!” After transmigrating into the body of a trash in a future where zombies and intellectual beasts existed, Lin Xiu accidentally obtained an upgrade system to transcend human limitations and devour the heavens!

One bad day is all it takes to send an average man to the fringes of madness, or so a wise, demented clown once said. But if one bad day that started with getting fired and ended with a meteor falling over one such average man's head didn't drive him insane, then maybe waking up in a fictional world full of monsters would do the trick? ... Are you sick of the usual power-wank, wish-fulfillment garbage? Are you tired of one-dimensional fanfiction protagonists? Have you had your fill of monotonous monologues and forced dialogues? Do you want to see steady, slow character development and power level growth? If you answered yes to all those questions, then congratulations! This is the story for you! ... I own nothing. All rights belong to their respective owners.

You can read my new book "Lord of the Time: I Can Reincarnate Infinitely." Fein is a transmigrator who finds himself in a world filled with monsters and demons. Fortunately, he has a unique ability that allows him to upgrade his talents in everything. Alongside his companions Aoi, Sofia, and Voli, he uses his newfound abilities to fight against the dangerous foes that threaten the safety of humanity. In this world, humans and beasts alike use the powerful energy known as degu to fuel their abilities, which can strengthen their bodies and weapons. Beasts are ranked based on their rarity, with common, golden, legendary, mythical, and god-level beasts being the most powerful. However, despite their strength, the beasts are not invincible and must be carefully fought. Fein himself can understand the laws that enabled him to gain powers such as space manipulation and the all the laws such as time, darkness, light, death, fire, etc... Space Manipulation allows him to create and control rifts in space, warp reality, and move through time. Meanwhile, Aoi has the power of ice and snow, which can freeze her enemies and create powerful blizzards. Sofia uses her power of destruction, and Voli wields the power of lightning to strike his enemies with devastating bolts of electricity. As they face off against the dangerous demons and monsters that threaten their world, Fein and his companions must use their abilities and their wits to survive. The battles are intense and the stakes are high, as even the slightest mistake could mean the difference between victory and defeat. Will they be able to save their world and protect humanity from the dangers that lurk around every corner? Only time will tell. You can buy my priv: Extremely Low Price at: Tier 1: Advanced 2 chapters- 1 gold coins. Tier 2: Advanced 10 chapters- 100 gold coins. Tier 3: Advanced 20 chapters- 150 gold coins. Tier 4: Advanced 35 chapters- 200 gold coins. Tier 5: Advanced 50 chapters- 250 gold coins. Disclaimer: The cover is not mine. The art is rightfully owned by Jenny Ann. However, if the artist wants to communicate to take it down, please DM me on my Discord--- UnluckyGuy#3859

Cross is the last of his kind, an extinct species wiped out long ago. Blessed with a strange power, he shall make a name for himself and make everybody remember the Blood Elves once more! https://www.pat reon.com/MonkeyGodking (BTW I suck at writing these! Just read it if you're interested!)