Way of Dark
Crystallize - Encase yourself in ice, making you immune to damage and reflecting projectiles. Lasts 2.5 seconds.
Cast time: Instant
Cooldown: 10 seconds
Crafty mages need their tricks. Crystallize is just what is called for when blocking deadly physical attacks or reflecting spells from afar. It's an instant cast spell, so it's there just in time when you need it. If you master this ability, you can even use it to send projectiles back at opponents who fire at you. At the very least, use it to buy time when waiting for a cooldown on a secondary ability.
Leads to: Soul Lord or Thaumaturge