So this build came from

So the first spell thats important is the wonderful Ignite that when speced into, gives 10 ability power while its on cool down, it also gives some levarage over players who are using heal to pop it after the first initial attack so you deal bonus damage and redue how much there heal is worth.
The Second summoning spell is Rally and although I have recieved alot of criticism about using it the reason behind it is to boost not only your attack and ability power but that of your allies also, which makes it perfect for team fights in general and during the pre-minion spawning if your in a double lane.
The combination of rally and ignite early on gives Kayle a advantage over other players by having a burst of ability power that allows her to shred through one if not both champions at the beginning of match.