MTL - Mysterious Young Master, Super Cool - Chapter 48 Can you ask me what is the difference?

Rhett never expected becoming king until he slayed an ice dragon out of self defense and fulfils an ancient dragon slayers prophecy which makes them to crown him as their king.Transported to a gloomy and medieval like world, he is faced with leading the dragon slayers, the weakest of slayers among other slayers - demon slayers, gargoyle slayers, ghost slayers and shadow slayers.But ruling isn't so glamorous as he had anticipated and he is instead a warrior, with a system like ability which he must level up by slaying Dragons.And to his disadvantage, the world he is his controlled by SLAYERIOUS, an unknown and unseen entity. But that won't stop Rhett, he intends on dominating his world and even daring to slay the strongest dragon still alive, ruieen.And who knows, he might just defeat SLAYERIOUS if he tries harder.[WSA 2025 ENTRY]

She is one of the best thieves that the world has seen in the 24th century. However, not even in her wildest dreams had she imagine that she’d be reincarnated as a good-for-nothing orphaned Seventh Miss of the Vermilion Bird Family. She finds herself stuck in a family that mistreats her, as well as an unfamiliar place with no support system.

This is the story of a young man who was reincarnated as a dragon with a near-insatiable curiosity. Initially sparked by questioning his own reincarnation, he quickly gets lost in the endless world of magic, using his deep understanding of advanced sciences to learn the laws and properties of a new type of energy known as mana.However, soon enough, the table would flip, and he would begin using that very same energy to expand his knowledge of science, to the point that he would begin questioning his own understanding of the world.Although not his original intention, with the combination of his intelligence, expanding curiosity, and the 'miracles' that occurred to allow for his existence, he quickly found himself climbing the mountain of strength as if it were a small hill before eventually climbing to a point where it seemed as if he himself was the peak itself.Even if.. that was never the case...There is mild gore, and profanity is 'censored' toward the beginning, but not later in the story.

Hell Ghost Wang Wannian is born again, smiling and proud!
What?
Are you a soldier, will the tank drift?
You are a master, can you give birth to dragons and tigers?
You are a superman, can you call the wind thunder?
Excuse me, I am not targeting anyone, everyone in my eyes, it is rubbish!

- Description from Uukanshu (translated)