In the first week, I built riders with a Castle and found a Tower of Archers. I didn't take the second town - one road was guarded by mages, and the other by dendroid warriors; archers weren't built, and I didn't have time to upgrade them.
In the second week, I took the Conservatory for 1 angel and broke through to the second town - gorgons blocked the road, so I only took the town at the end of the second week (Rampart). I built elves there and captured the Unicorn Glade.
In the third week, I broke through to the third town - Necropolis. I gathered resources.
In the fourth week, I took the Conservatories - 4+3+3 angels, then went for the Book of Earth Magic - I saw it in the Dungeon. On day 147, I positioned myself near the Great Oasis.
On day 211, I broke through the Great Oasis (~110 Storm Birds) and took the opponent's empty capital. Two days later, I stormed his secondary town with Kairi - he had no chance; Valeska was stronger in terms of stats, army size, and magic.
Thank you for the game.