(After leaving my d20 with the 20 side up, I make a roll, and it Is 18. 18+7=25. For now, I'll assume I have first Init.)
Aerda stops the horse and turns to what victus points out. He narrows his eyes, and closes his eyes, holding both hands out infront of him. He starts speaking words of old draconic, in a low voice of power. Long thin fingers paw at the air in complex patterns, gathering a shrill energy to them, forming it into a sphere. He holds the sphere out and opens his eyes. With one hand behind the sphere and another one under it, he pushes it forward at the lead skeleton, the white light it shed leaving aerda's fine features and racing towards the running creature. Concussive disturbance in the air are its wake, and Aerda looks at the others.
(Ranged touch attack, rolled 11 + 4 = 15)
Edit: I forgot that it was range, close, so I will ready that for the first person who comes within 30ft.