Inferno tactics.

Inferno is the strongest castle; you can gather demons in huge quantities there (and this isn't prohibited, right?). However, when using templates (for example, the most popular one, 2SM4d(3)), its advantage is lost because the game doesn't last long, and you simply don't have time to create many of them. I think that precisely because of its ability to gather demons, this castle was made less powerful than some others. You can even compare Inferno to Necropolis (you need to eliminate both of them early on, before they gather a huge army). It turns out that the castle's strength is diminished by the template. It's just tedious to create these demons...