Chain Lightning

Caster Level: Wizard/Sorcerer 6, Cleric 6 (Air Domain)
Innate Level: 6
School: Evocation
Components: V,S
Range: Long
Save: Reflex 1/2
Spell Resistance: Yes
Area of Effect: Colossal, 1 Target per level
Duration: Instant
Additional Counterspells: None
Description: A bolt of lightning arcs through the casters enemies dealing 1d8 electrical damage per caster level to a maximum of 20d8 to the initial target and half that the rest.