Walkthroughs for custom maps.

In the second-to-last mission, you can learn a lot of useful magic in the Castle (if you're lucky), which will be very helpful in the last one. But it's not easy to do – an enraged Dream Demon can wipe out your units before you even reach them)).
But yes, in the last mission, vampires are the best.

Yes, that's true. You can also buy heroes in the Castle of an ally when he starts to repel the Ramparts. We defeat Karasuchka using peasants or a box (there are no special defeat conditions here) and visit all the Castles at the same time as the ally. But playing this entire campaign without Eagle Eye is quite masochistic :D

Added 5 minutes later

That's why I gave it a dislike. Because it's not right. :( Or maybe it's just a coincidence...

This reminded me of the Rise of the Sun King map. I looked at it very carefully, and there is a similar trick in front of the outer tavern and the fort on the hill: each visit threatens the loss of a significant amount of money.