LazySageDao
I'd avoid categorizing magic based off worlds. I'll stick with the type specifics of charms, rune, soul, arcane ect. Then if he needs to further describe it, then you can tell us what magic system he used to further broaden these schools. I'd also like to see the Elder Scrolls world too. You can make gods their absolute unlike in HP
Author you screwed up this chapter. From what you've wrote so far either herpo should have been the one that sent the dementors and Edward should have found a way to deal with him after that or he was the dementor king. Either way there's no way that death stood still and did nothing in 35 years. Also don't leave this world and leave unfinished business with him. Anyway what's up with the Korean dungeon break theme you wrote? It was a little cliche and cringe in my opinion
Author here's my suggestion... A serious issue with magic systems is some of them are inherently incompatible. Example- Ki/Qi/Prana are all forms of energy... But they all work in different ways. My suggestion is to simply have him encounter a small bump during his first dimensional travel... Altering his core/soul in some way; making him compatible with all/most forms of magic- while retaining independence from the worlds system. You could effectively design Edwards personal magic rules; and any knowledge would simply be that... Knowledge. Akin to moving to another country to learn their culture. This could even explain Rowena's anomaly; due to her encounter with the gap between worlds.
I'm sorry but I completely and utterly dislike this chapter. Was this some fake event he created to attain authority? Fake as in he made the army and so called king to make use of the conflict for power. That's what this seems to be and it was thoroughly unpleasant and fairly annoying to read for me.