All castles in Heroes 3.

Chain lightning, based on and advanced with 4 bolts... at least on expert difficulty, it's like that in Armageddon... if I understand correctly, the damage from each lightning bolt is divided by 4. For example, if the opponent has 4 units, and the lightning deals 500 damage, the first unit receives 500, the second receives 125, the third receives 31, and the fourth receives 7. It then bounces off the unit with the mirror spell and back into those four, dealing 1/1/1/1 damage to each. It's nonsense... although maybe I'm just rambling.