Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Crit 63.5%, Power > 400 and Speed. This is gank and run build. Because of the low HP it relies on the power output from the combination Mejai's Soulstealer, Lich Bane, Rod of Ages, Infinity Edge.
The ability power will get very high after a few ganks (Mejai's Soulstealer) and as time goes on (Rod of Ages). Mine has easily gone over 500 and w/ over a 50% crit chance you are bound to floor everyone. I added the Lich Bane in there because of the 250% bonus on crit.
In most cases you will see people's hp go down for 1/2 to 3/4. Almost all will run for the hills as soon as the stun wears off (if they are alive). It is purely psychological to flee if you are nearly dead. In most cases they will run for cover so re stealth and find them safely for a second ravage.
This is where I chose to flash for a quick kill so you can get out alive. We all know that chasing is bad because you have a high chance of getting ganked in the process.
To prevent from dying get a few levels under your belt, 3-6 and get out of the lane. This allows you to communicate w/ the other lanes for coordinated kills. In turn you will gain levels fast.
So hide in the bushes, look for people w/out a potion on, Shadow Walk, Ravage, Hate Spike X2 - X4 and get ready to Flash.
Focus the most attacks/kills on people who are wounded. You will pound them w/ Mejai's Soulstealer + Ravage
Oh and I chose heal cause I tend to stick my nose out too much some times.