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.
Most of the ppl thinks that sion=tank, but it's not true... sion is an OP dps.
He almost impassible to kill while you using your ultimate(20 sec), it's usually enough to get double/tripple/quadra kill
With this build u have enough crit strike and attack speed(specially when your ulti is on) but u might need more AD or armor penetration(i prefer AD)
as a first item get Vampiric Scepter, then update it to Executioner's Calling then how it said in a build... u ending up with > than 100% of crit strike, so fell free to sell calling and get frozen mallet or bloodthirster or last whisper depend on enemies
u need Cryptic Gaze first specially if you planning to gank and bring first blood to your team, second spell should be Enrage(once u learned it press "E" and NEVER press it again XD ). Vampiric Scepter will give u enough lifesteal so u wont be wasting your HP on Enrage, and this spell gives you good amount of AD for early game that's why u wont need any AD items untill u will get second phantom.
You should do enough dmg so enemies will run as soon as the saw you, that's why u would need ghost and exhaust, so you can catch them ->> stun ->> kill easily