Wisdom of Demons

I played through the game with a hero, simply taking 40 attack and 40 knowledge stats, and spells weren't even needed. True, I got firearms at level 28 (perfect timing). The beginning was interesting, then another 2-3 battles near the portal where the mages spawn. After that, even a level 1 hero could easily defend the city with a large army. I just used auto-battle to clear everything. Actually, the mages started to become a problem around the 4th or 5th time I entered. I think it could be limited to 2-3 spawns from the portal.