Inferno vs. Haven

In a duel, one user employed an interesting tactic against me using demons, although I was playing as Sanctuary. He defeated me the first time, but then, knowing how he would act, I defeated him. It should work against humans as well. There are large demons (I've forgotten the name) that draw the attacks of all nearby enemies. In the battle, he brought these demons close to my troops and cast Petrification on them – a spell that prevents a unit from attacking for two turns if it doesn't attack or move itself. As a result, part of my troops lost a turn trying to move away from the petrified demon, and they couldn't attack the enemy while being shot at and torn apart by spikes. Plus, they couldn't attack nearby enemies in melee for two turns because, when approaching the petrified demon, they would switch their target to it and couldn't harm anyone else. In other words, for one turn, part of my troops didn't attack at all, and in the second turn, their attacks were limited to only a few units, rather than any units of my choice. In the second duel, I defeated him because I destroyed these demons in the first two turns, before he could cast Petrification. In my opinion, the guy has a brilliant trick, and there should be others as well.