While looking for scenarios, I decided to replay some old ones. I came across this one and found that all the links were broken. But I have my own archive! So, I'm posting this scenario here for myself and for others who might need it. https://disk.yandex.ru/d/PCN2dDvK2ubI2Q
P.S. The Avatar's garrison can be bypassed; all the spells on the map are focused on summoning. It's essential to have a Pet with the "Rooster" skill to level up, otherwise, there aren't many places to learn spells. Summoning and Darkness are the key here. The map is easy; the only problem is at the beginning on the Great map.