Houssem
AUTHOR! I suggest the BAKI universe for the next world, it is reasonably stronger than Demon slayer, and the progress of the martial arts of the Mc will be gigantic not even speaking about all the truly EPIC fight scenes you can make taking dozens of chapters to FINALLY reach the strongest creature, at which point the Mc can win on lose. And to recite a bigger challenge and as a result better results the Mc can even teach a breathing method to the characters.
Amon91:you are wrong tho demon slayer as a whole is stronger than baki unless you are speaking about martial art