actually u can do tt,instead of using blizzard as base spell,use inferno which summons a dummy unit and has a height so it looks like it comes down from the sky,then give the dummy a cluster rockets spell with 0.1 stun and switch the art with arrows.(if u want it to cast spell upon attacking its in one of the triggers but i 4get which 1 issit and theres another trigger that causes the dummy to attack the area it spawned).....oh yea the dummys attack range shld be arnd 500 depending on ur cluster rocket AoE,and its aquisition range shld be short if u dun wan the arrows to fly somewhere away from the casting area