There are seven runes to collect in the game. Each one can do some good for you in combat:
Fehu - Instant Damage Radius
Damages all enemies in a close range around the player
Othala - Ranged Stun Attack
Blast your enemies with force. This rune replaces your power-attack with a ranged bolt that stuns a single enemy.
Hagalaz - Instant Multi-Target Damage
On activation, tap on screen to target desired areas with a meteor strike, each dealing damage in a small radius.
Dagaz - Channeling Healing Effect
Channel magic power to heal over time.
Sowilo - Ranged Damage Cone Attack
Multiple waves of fire emanate from you. This rune replaces your power-attack with a cone of damaging fireballs.
Isa - Instant Stun Radius
Stuns all enemies in a range around the player.
Kenaz - Instant Mana Recharge
Instantly recharges your mana reserve.