Claws of Guthix

Claws of Guthix requires 60 Magic and can do a maximum of 20 damage per spell, or 30 when the Charge spell is in effect. Players must complete the Mage Arena and be wielding a Guthix staff or Void Knight mace before they are able to use this spell. It can only be autocasted with the Void Knight mace. The Void Knight mace costs 250 Pest Control points from the Void Knight Outpost, and the Guthix staff may be bought from the chamber guardian after stepping into the sparkling pool in the mage arena for 80,000gp.

Claws of Guthix lowers the target's Defence level by 5%. Previously, if the target's Defence level was above or below the normal level (such as after using a Defence potion), the Defence level would remain unchanged; this was fixed on January 10, 2007.

Claws of Guthix seems to be the more efficient God Spell, as it requires less runes than Saradomin Strike, and air runes are easier to craft than the fire runes needed in the Flames of Zamorak. It can also be autocasted.