Discussion about Dungeon (Dark Elves).

I'm just starting out and taking it to unlock access to Secret of Destruction (+2 to knowledge), otherwise, you can't cast many spells with only 10 mana. The Dark Ritual itself is good when you're simultaneously leveling up two heroes – one fights, and the other skips a turn nearby because they spent their mana. On the next turn, they switch places, and resources are captured faster.