I suppose giving some updates in this thread could be useful, so here we go.
Been about a week since I made some base of the code, looked at it this night and noticed I was really overthinking what I was trying to do. So, lots of nonsense was removed and some stuff redone. Today I managed to get the 'loader' working along with overhauling a bit how things are handled and how rarities / effects are made. The loader is basically like a tml loader, and allows for some easy autoloading for mods. Yes, this means other mods will be able to make rarities and effects, and those can be autoloaded (or manually loaded, but of course everyone will autoload)
Still thinking through some stuff on how things should be done/handled, which I want to take my time for because making the actual contents of the mod will be fairly easy when everything is laid out properly.
So right now internally it works like this:
An item can have a modifier, the modifier has a rarity level and a collection of effects
The effects are what is actually influencing the player, or the item, etc.
The rarity of the modifier will be based on the sum of the effects' strength, just like how it used to be
And also like usual, effects will be able to roll their own magnitude, which can possibly affect the strength etc.
Also, I might make it so that modifiers reroll on a reforge, and possibly add a way to lock the modifiers so it rerolls the magnitudes.