Way of Dark
Frost Flood - A massive AoE spell which hits for 1 heart of damage.
Cast Time: 2 seconds
Cooldown: 8 seconds
The long cast time of Frost Flood is offset by the large radius. But make sure you have the sense to pick the right time and place for this spell. Enemies will know its danger; so distract them with another spell or even an ally who will lure them into your blast radius. When choosing a secondary ability, something with an instant cast time is highly recommended.
Leads to: Craft Keeper or Warlock