I don't remember the quote exactly, but there one who goes like :
You need a year of sword practice to use it and ten years to master it.
But you only need ten days to use a spear but a whole life to master it.
Spear are easier to use, but harder to master.
I like swords, but they can't...
All You Need Is Kill
Kekkaishi
666 Satan
Tokyo Revengers
Deadman Wonderland
Eyeshield 21
Ajin
Claymore
Soul Eater
Magi
Break Blade/Broken Blade
Negima (It's pretty boring until half of the manga tbh)
Kateikyoushi Hitman Reborn!
Nurarihyon No Mago
Beelzebub
Air Gear
Holyland
Marchen Awakens...
It depend if it's written by chinese authors or not and if it's Xianxia, Wuxia or Xuanhuan.
There a logic behind Xianxia and Wuxia written by chinese authors, the first few realms are often the same and came from their culture often taken from taoism, budhism, and they include traditional...
If you want some references, you can try to read Martial World, be it for the cultivation realms or any other reference such as techniques, soul realm, contracted beasts, forging, inscriptionist, formation master, etc.......
If you like junk food, you have Pocket Hunting Dimension
You can also try Astral Pet Story who have a system that "look" like this with the mc going to another world and having respawn ability.
Don't use our rules for other races, even in our own race the age of consent change depending of the country and the era.
What really matter for most readers are if the individuals related to those scenes are mature in their mind.
You have to make your MC think to protect itself and move its summon to do it, unless you go the path of your mc becoming stronger and even more than its summon making the summon theme useless.
Lazy Dungeon Master?
Didn't read all of it, but it seem to fit.
The mc get summoned by a dungeon core, but he become the ruler of the dungeon and use the dungeon functions to create things so he can live a lazy life.
Not really introvert, but that kinda fit.
Name: Elepharak
Story Description:
The beast had a slender silhouette. Its head was covered by what appeared to be a black helmet made of extremely thin rock with two spikes on each side of its head rising upwards, resembling two horns, a white light that had the shape of an inverted cross...