Chains Of Fire

Evocation [fire]
Level: Magus * 6, Sorcerer */Wizard * 6
Components: V, S, F (a drop of oil and a small piece of flint)
Casting Time: 1 Standard Action
Range: medium (100 ft. + 10 ft./level)
Target: one primary target, plus one secondary target/level (each of which must be within 30 ft. of the primary target)
Duration: instantaneous
Saving Throw: Reflex half
Spell Resistance: yes
  This spell creates an fiery discharge that begins as a single streak of fire commencing from your fingertips. Chains of fire strikes one Object or creature initially, then arcs to other targets.
  The chain deals 1d6 points of fire damage per Caster Level (maximum 20d6) to the primary target. After it strikes, it can arc to a number of secondary targets equal to your Caster Level (maximum 20). The secondary chains each strike one target and deal as much damage as the primary bolt.
  Each target can attempt a Reflex saving throw for half damage.
  The Reflex DC to halve the damage of the secondary chain is 2 lower than the DC to halve the damage of the primary chain. You choose secondary targets as you like, but they must all be within 30 feet of the primary target, and no target can be struck more than once. You can choose to affect fewer secondary targets than the maximum.