Necropolis discussions.

Phoenix isn't that great, but when you're low on mana and need to cast it again, it can be useful. Even if the Phoenix trick doesn't work, Crystal is a very good spell. Elementals are generally excellent; if you take the fire skill, they'll take out everyone from a distance, and they're summoned 40% more often. Mines are generally considered a cheat spell in the League. So, even without Phoenix, there's plenty to explore with Summoning.