some help with a spell

some help with a spell

I am new at this but can some one tell me how i can make it so taht an aura will have the Pheonix fire

the pheonix im talkin about is the ulti of the bloodmage you know how it shots rays out i was woundering if i can make a aura that shoots out rays at enamys for a matter of secs and the higher lvl the longer it stays

for all i know you cant change the duration of the projectile. and because its a projectile, it might last shorter than a lightning. but you can use dummies to make the effect

ok thx