You start out with a dorens ring then stay in mid untill u have about 4000 gold then return and buy your sorcers shoes and your archangels staf. After that just fallow the build in order
If the other team isnt building magic resistance then go for a Archangels instead of void because if u have archengels then by the end of game u should have about 1000 ability powere!

If you want while you are in mid and the enamy is back a base then go ahead and go for your blue.