Public/Main/Stats/Generated/Character.txt is the file you want to look at (if you have unpacked the Main.pak file), since that is where all of the stats are defined. You can make your own txt for your mod that replaces the data entries for each character stat in the game.
Certain enemies would be locked into a certain level (due to having a level override), so you might also need to overwrite the level overrides for specific characters so that their stats scale appropriately. You can use the editor to save their character data into your mod's equivalent folder, and then make changes.