Start on "Hero".

I used to use it too, but as far as I remember, it consumes a lot of mana, and it's not very well developed. I'm currently trying to play on maps for 6 players.

I wouldn't say it's weak. Immediately upgrade Skilled Chaos + Pyromancy. Look for a Phoenix Feather Cloak near the castle or in the shop. At the beginning of the game, also set a random artifact bonus - maybe you'll get lucky. Mages don't have problems with mana.

I remember how, in the first week, I had to defeat about 70 or more red crossbowmen. There was no guild yet, nor a Battle Standard. I put 7 gargoyles, each with 1 hit point, into the battle. The crossbowmen split into 4 squads. I destroyed 2 stacks at a time with a Fireball and won the battle with almost no losses.

And against high-level creatures, the damage from the Fireball is not as important as the 50% defense reduction.