Ring of Blades

Creation [Force]
Circle: Shaman 5
Casting Time: 1 standard action
Range: [Medium]
Effect: Line of force blades; or see text
Duration: [Encounter]
Saving Throw: Reflex half or negates; see text

You create a wall of whirling blades of force. When you cast this spell, choose either line or spreads. If you choose line, you create a line 5 ft long per level you possess and 5 ft wide originating from target square within range that lasts until the end of the [Encounter]. If you choose spreads, you create a spread with a radius of 10 ft per 5 character levels you possess originating from target square within range that lasts until the end of the [Encounter], then remove all squares from the spell's area of effect within another spread with a radius of 10 ft per 5 character levels you possess minus 5 ft originating from the same square that lasts until the end of the [Encounter].

For each creature, the first time each [Round] that creature enters or exits a square in the spell's area of effect, ring of blades deals 1d8 physical damage to that creature per character level you possess. A successful Reflex save halves this damage.

When you cast this spell, a successful Reflex save allows a creature within its area of effect to gain [Immunity] to damage from this spell until end of turn and move 5 ft.