How did you defeat the leprechauns with an Imp? Did you make a mistake, or are you referring to Sandrik?

How did you read our discussion here? Everything is written. For example, on the first day, I gained 100 mana for my Hero by fighting leprechauns. And Zveroboy managed to buy a second Haven Hero and was able to recruit 5 Fairies.
Try reading all the posts in this thread, starting from the first page - there are only three pages, and also read the rules carefully. Everything will become clear - there are no secrets here. Zveroboy defeated skeletons with 1-3 Fairies, and I used one Cerberus.
It's not a pleasant task, but it's doable :)