Combining the power of creation’s First Song and the magic of the Primal Origin, Worldsingers often express abilities that join magic to music. Of the class combinations most often entering the Worldsinger path, many of them are of both druidic and bardic progressions and among there lore is a particular knack of fusing the raw elemental energies of the Primal Origin with the inspiration they lend their allies.
For the Worldsinger mythic path from Mythic Paths of the Lost Spheres:
Spellfire Song (Mythic)
You ignite the elemental power of your magic to carry along the music of your song.
Prerequisites: Carrying Chord mythic power, domain or bloodline with an elemental type.
Benefit: As a standard action you may sacrifice a prepared spell or spell slot available to you to add 1d6 of bonus elemental damage per spell level of the spell or slot sacrifced to the attacks of creatures benefiting from your morale bonuses for 1 round. The elemental damage is of the same type affiliated with your domain or bloodline. Alternatively, you may expend a use of mythic power to activate this ability as a swift action.
You can get Mythic Paths of the Lost Spheres on: RPGNow or Paizo or d20.pfsrd.com!
"Find the Hero Within" - Lost Spheres Publishing 