Start your W because W is the best. Get your stun ready for that level 2 fight.
Get Q second. Then E third. Keep spamming for stuns 24/7.
Max W, then Q, then E.
Get a faerie charm, x2 sight wards, x1 vision ward, x2 health potions
you're then going to build a sightstone
after sightstone get a void staff
after void staff get a athenes
then you need to sell your sightstone because you don't need wards anymore
get your sorcerer's shoes
get an ohmwrecker because you are a siren
after ohmwrecker you should win the game but if not go for a 1. deathcap 2. zhonyas 3. will of the ancients
and thats all