Once you get some good enchantments, you can become a god even with the leveled system. However, there are some mods that cap certain enemies at lower levels like bandits, mud crabs etc so you'll kill them easily at higher levels while other enemies remain challenging. There's probably a mod that sets all the monsters to a certain level regardless of your level as well. Basically, get some mods
BTmod is quite good, as is no psychic guards.