Unicorn Empire

Hello everyone. I have a question: how do you kill Death Harbingers in mission 4? To kill them effectively, you need either Mummies or Death Knights, but I don't have them.
Let me explain a little. Instead of Death Knights, Death Harbingers appeared on my map, just like on the Swarm Lord map. They have 300k HP and 1500 attack. But on the Swarm Lord map, they are part of the scenario, and you get Death Knights to kill them. Now, they have appeared on other maps, and I don't know if they are part of the scenario or just a bug.

Hello everyone! The campaign is amazing, but there's a problem, similar to Rambo1969 - the game crashes in mission 2 on the night before the start of the new week. Nothing helps (I've restarted it about 50 times, reinstalled the campaign). Is there a solution?