Grover’s Expedition

Thanks for the tip. It was hard to figure out, as was the fact that you can't use the tear in the city (this should have been mentioned). Now, about something sad. Nibros is, of course, a cheater (a fan of dark magic), but we are winning. I switched from Chaos to Light and took the corresponding tome. As a result, with the help of acceleration and a punishing strike (and when necessary, removing spells), I defeated all his troops. But here's the problem: the battle didn't end with that; he casts spells without troops. I'm seeing this for the first time. How should I understand this?