What spell combinations are there?

I said “at the beginning of the game,” when the hero is still far from having access to 4th-level spells (Cat’s Agility), but obtaining a 1st-level spell from the opposite school is quite possible. Furthermore, at the beginning of the game, there are few Medusas, and for the petrification effect to work, the Medusa squad needs to have a 50% chance of killing at least one unit from the enemy squad; the probability decreases as the level of the enemy monsters or heroes increases. To use the infinite ammunition tactic, you need to prevent the enemy from engaging in melee combat, which is also problematic at the beginning of the game.