I found a special unit in the game called Infernal_Machine, which explodes with a fireball upon attack, but I noticed that it doesn't work. The fireball itself explodes, but it doesn't deal any damage. I noticed an interesting fact: if you give a demon lord the Hellfire spell, the fireball starts dealing 1 damage. Is this a useless unit, or is there a way to revive it so that the fireball deals damage? If possible, how?
I tried giving the fireball as an ability to a hero – it didn't help.