At this point I would really suggest you read the web novel. The translation is good and the parts after it are easily readable with Google translate. The novel has a lot more depth and world building.
Here is a link
https://bayabuscotranslation.com/demon-king/
MC background before reincarnation kind of explains why he is a jerk.
There is no magic in this world. they are called witches because they were apothecaries and created medicine and "Potions". This is also a matriarchal society except for the knight families.