Ai is a litte problem.
The main issue is the enemy's in the game dont have abilities acording to they lvl. For example a lvl 12 wizard have magic missile misty step counter spell and that's it and mybe 1 more cc. There is no challenge its not about the ai.
Lvl 12 - 16 enemy's have 14-21 armor class and that's it. Armor saves spells abylitys are not existing.