need If x mob on screen use x spell !!

am hunting in yalahar necros, but now and then necro runs east (whare hellspawn is spawned ) but the scirpt runs when hellspawns (lose target) shows on screen but the character is not fast enough and he dies.. i want a script that makes if hellspawn comes on screen so it makes utani gran hur and it will run fast enough from the hellspawn !
Would be g8 for help !

You can add special areas so it avoids going far west to hellspawns. Also for your request:

auto(100)

if not $hasted and maround(10, "Hellspawn") > 0 then

cast("utani gran hur") waitping(2,3)

end

Thank you !