How to recruit a level 8 monster in your "home" castle.

First, you capture a level 8 monster dwelling on the map. (Let's say—Thunderers). Next, it is MANDATORY that you own a town associated with these monsters (in this case—Tower). After that, it's simple: when you recruit level 7 monsters in your town, you can also recruit level 8 units in that same building. A third monster simply appears there—unupgraded, upgraded, and level 8—all three side by side. (for example—Giant, Titan, Thunderer). You can then recruit them there just like regular units. The quantity depends on the external dwellings you have captured. For example—you captured 3 external Thunderer dwellings and immediately recruited 1 Thunderer in each. At the start of a new week, you will be able to recruit 3 Thunderers in your Tower. It is all quite simple.