Hey guys! This build utilises what I find to be Sion's strengths and take advantage of them. After this you should be owning every match. Goodluck and enjoy. This is a very simple build making Berserker Greaves, Infinity Edge, 2 Phantom Dancers and a Bloodthirster. Please leave some constructive feedback below if you see sny improvments thst need to be made :D

The runes that i have chosen combine Crit chance, Atk speed, Atk Dmg and move speed to make sion show his true potential in the form of rape.

The masteries 21/9/0 is a great tree build up for sion. In the offense tree picking up as much damage as you can and crit and atk speed and in the defence tree picking up as much health regen as you can. Health regen because your E (Enrage) uses your health as the cost per basic atk so you want to be able to regen that A.S.A.P

These items will show you how sion can really chase or run with his move speed plus ghost if you need it. Starting of with a Dorans blade gives you that atk dmg that you want plus some health and a little bit of lifesteal that my help you if you crit, follow up the Dorans blade with Berserker Greaves, then Infinity Edge, after this get 2 Phantom Dancers this is time for you to start chasing or running which you won't need to do with this build, get a Bloodthirster you will need this so you can heal more and hit more with your ulti, finally if the game goes long enough sell the dorans blade and buy another phantom dancer. enjoy your build :)

With the order that you level up your skills you need to focus on maxing your E first (Enrage) then max your stun which is your Q (Glare) then obviously your W (Death's Caress). Oh but obviously when you can level your ultimate up do that.

For your summoner spells pick up ignite and ghost up. Ignite will help with those kills that might get away from you early game and pick up Ghost because with your 2 phantom dancers and ghost im sure you will realise that sion will be extremely fast and he wont be able to be caught or the enemy wont be able to run.