This is the Sion build I use on Twisted Treeline. Remember, items can vary depending on who's on your team and who you're versing. In you're laning phase you just want to harass with stun shield explosions, but don't bust your mana. Last hit with (E) or you're shield. ONE more thing, please don't rate or comment on how I play Sion (or build him) Rate and comment on how I play AP Sion. I'm tired of the controversy between Ap and Ad Sion. Thank You :) Feel free to rate and comment :)


Some Laning Advice: Early game just last hit minions, occasionally harass with you're stun and shield if you find an appropriate opportunity. Mid-late game, you will be able to gank very well : Activate shield, Flash in, Stun, Blow up shield. After that sequence the target(s) should be dead. End game your stun and shield will be doing about 2000 - 2400 damage and lichbane will make your auto attacks do like 700 - 800 damage.

For you're first item I reccomend either an amplifying tomb, witch will lead to Mejais, Or a mana crystal, witch will lead to sheen. Now, for boots, if you're looking for some extra damage I'd get Sorcerer's Shoes, but remember Mercury treads are always better if you're versing a team with decent CC. Mejai's Soulstealer is not a must have. Only get this item if your confident you'll be doing good. Now items like abyssal scepter are obviously better to have when you're versing a team that dishes out high magic damage. Although you can substitute items like zhonya's hourglass(for ap and armour) Rod of ages, or any other items you find good. Now if you find you're dieing to fast or getting focused, I'd suggest items like Guardian Angel, Thornmail ( for those extra heavy Ad teams) , Or maybe a force of nature ( for those heavy ap teams ) But remember Abyssal scepter doe sgive Magic resistance so usually it's a better choice, Just like Zhonya's Hourglass gives armour. Rabadon's is a must have, it will multiply you're ap greatly. Lastly we have the Lichbane, just as usefull as rabadons. This item will empower you're next auto attack with your ap, after you've used a spell.

Flash: Always good for Sion, allows for easy ganking. Flash in stun and blow your shield for incredible damage. Flash is also useful for escaping.

Clarity: For my Sion build you won't have much mana, however masteries will help you with mana regen, but either way clarity is great when you just need a little bit more mana to get that kill.

Cleanse: If your playing a ranked game and you notice the team your versing has high Cd, cleanse is never a bad option

Ignite: I don't personally like to use ignite but some people do. Good when versing characters with high lifesteal or high regen (Mundos a *****) And just to get that insane kill.

I would avoid using things like Fortify, Rally, Heal, or Teleport. They can work but I find clarity and flash is the best for Ap Sion.

The runes I have chosen are typical ap runes.

Marks: Spell pen, you're spells will do more damage, quite obvious and basic.

Seals: More flat ap good for early game.

Glyphs: Flat or scaleing ap Glyphs work fine, personal preference mostly, Flat is better early game, Scaleings better late.

Quintessences: Ap quints for good early game ap.

I've gone 9/0/21 becuase you want the extra 15 % spell pen from offensive, And the extra mana regen and summoner spell cd reduction, along with points in flash (15 second less cooldown) And clarity.

Pros

-Ap scales 1 for 1 for two of his spells
-Great Aoe burst
-Long stun
-Great health and easy last hits thanks to his (E)

Cons:

-Doesn't have steady damage
-Ult is somewhat usless,(for ap Sion) can help you stay in lane though
-If his shield is destroyed he loses a vital part of his burst

You're mostly there to stun, and blow up you're shield for great Aoe damage. Keep your distance and go in when your shield or stuns ready - Protect your squishies with your stun as best you can. You can pop you're ult, it won't do much seeing as you're not Ad, I mostly use his ult to stay in lane longer.

Ap Sion has great Mid-Lategame Farming with you're shield but early game it can be hard, Just try to last hit with your (E). Jungling gets easy around level 10, just use your shield to kill the mobs, but don't ever jungle straight up, unless you're an Ad sion, then it CAN work. Ap Sion however is a laning charater, and he's good at it. But don't be afraid to pick up some extra buffs every now and then.

Well this is my Sion build, I hope this guide will help you and keep playing Ap Sion :)

Sion is quite a unique character, he has an Aoe spell that scales 1 for 1 with ap. If you use this move properly you can change a fight that seems impossible. With your stun and shield you can basically one hit a squishy mid-late game.