you start of with Boots of Magi I, Meditation & pots.
you start with Boots of Magi II and Pots.( the build is different cause u have to go once to base when your level 4 and about to reach level 5 to ready your invent. Your level 1 ulti is very strong to use it to fullest you should be ready with your best possible invent)
Mid Game :
Solo Lane :
At your level 5 you would be pushing very hard mid lane unless your against either ra anubis or an enemy ao,
if its Ra or Anubis you should be harassing them hard enough to keep them tower hugging.
Never tower dive with Ao your too fragile with this build.
when u've kept them away give one ulti hit harass n when they are busy at their towers with their creeps you can make your move to a side lane gank. you will be technically faster than your opponent in mid lane because of ur creeps at their tower and ur 2nd skill making you have a bit of a head start.
Side Lane :
When you are nearing Level 5 put a trip to base get your invent and on your way back to your lane call for a gank.
( probability of taking the kill with Ao in this gank is near about 40% not more so dont push it too far- be the one to call retreat if you're gonna be risking too much going ahead)
you will be capable of ganking mid lane with a bit of mid help ( if u secure a lane kill call for a tower push in lane )
believe it or not Ao can push hard at any lane.
Ao's Best advantage
With the build described above Ao is capable of magic power over 800 which is a huge advantage with his polynomicon. His best advantage is his capability to chase the enemy for a sure kill. Activating his second skill gives him the MS increase to narrow on his target with a polynomicon hit he can finish his enemy ( and the dragons fangs secure the prey).
chase kill combo
skill 2 , move forward hit, move forward , skill 1, hit,tornado target, hit again ( with gem of isolation the target is near about dead)ulti for a secure kill.
this same skill combo can be used for taking towers. ( 3 polynom hits will drain the tower health though it needs this combo twice to kill.)
Turning the Tables
Ao is the best bait, people see his low health pool and try to take the kill but with his 2nd skill animation and his ulti activation animation similar u can activate ulti and 2nd skill together when they enemies are near and bait them to the path of the ulti once they get on the path get ready for a tornado and squall combo which the moment u finish casting run away. your advantage of speed from slither will help you keep some distance to later go in for a Chase Kill Combo or retreat.
Worst Enemies :
I would never have said it enough times, but Ao is very squishy in this build so Stunners are people you have to be careful about.
Hades is trouble so dont forget to get a void stone when you face him.
Purification for wukong would help you loads as wukong cannot catch up to slither.
But these are not His worst, Always and always be in the lookout for ODIN !!! Odin is the dragons worst Nightmare, he's got the health to tank you, a ring of spears to cancel out ur escape and the damage to wreak havoc.
When facing your worst enemies always stay out of harms way, ur advantage is to cause damage without being in the area of the battle use it to ur advantage and Dragons Rule !!!
Its my first attempt at a guide, so I'm not sure of what all data my readers would require, I'd add more from time to time if I can.