Hi I am blo0draven and this is my first guide on Mobafire.I know it will be far from perfect but please give it a chance.I am not a top Elo player,but I try my best and I am always opened to constructive criticism.With this build I will try to show you how to make him a good 1v1 solo top and a perfect team fighter.I am really sorry for the English mistakes.Credits to jhoijhoi for her guide on how to make a guide.

You get this for easier last hitting. You get this because you use Flash, Ghost and/or Ignite. You get this for the AS buff it helps. You get this because the armor reduction helps a lot.
The other points in the offensive tree are not that good or they explain themselves but you don't have a better option at the moment. 1 point in the first and 3 in the second or the other way around depends if you are facing a AP or AD solo top.
The other points in the defensive tree explain themselves.

I get those for help with the late game damage when you have a lot of critical chance.You can get Arp quints or flat AD quints but i think these will help more.
I get those for better last hitting you could get Arp marks but i do prefer the flat AD.
Seals: I take those because 99% of the times the solo top or jungler will be AD and as the solo top you will probably have to fight them.
Glyphs: It is almost for the same reason because of the seals.I get these because in 99% of the time the solo top or the AP mid will be AP and you will probably have to gank them or 1v1 them at some point in the game.[/center]

can get you a better position faster or get you through walls but works better with Sion because he need to say next to his target at all times. is used to finish off someone or to make their healing worse.
Less Viable Summoner Spells: can be used to bait someone or to dominate lane but it doesn't work better than Flash,Ghost,Ignite with Sion. can be used to defend towers or help team mates but again there are better choices.
The other spells are so bad that there is no need to explain why I don't take them.

This passive is underrated.It helps a lot in laning phase. This is your initiation tool.You can also use it to control a fed person.If you will have a level 1 fight take this This helps you a lot early game but you almost don't feel it mid and late game.Normally pick this on level 3 and max it second. This is your AD steroid.Only with this and a few items you will have amazing damage.In a normal game you get this first for two reasons.First for easier harass and second for better and easier last hitting. This must be used only in team fights it is one of the best ults in the games but you must not waste it.You can use it for 1v1 only before the team fights start and may be for baron but it is not a such good idea because a lot of battles happen around baron and you might not have it when you need it.

With the items,masteries,runes you start you shouldn't have a hard time last hitting.That means that you should try not to push and only last hit because that way your team could come and help.Of course if you are winning the lane you can push the enemy creep wave to its tower so the the enemy loses experience but that is risky because he could freeze the lane and give you a lot of troubles with farming so be careful.
In team fights you should be the first or second person in,you should stun and kill the most squishy targets in their team that also deal the most damage 99% of the time.Never forget to pop up your ult even if you see you are about to die because you your ulti is very good and it might save your life or at least you could help your team a bit with the heals.

You should get ,5x if you are against an AD solo top.If you can exchange hits with the enemy solo top in your favor then you could try to go for an early kill.Remember not to push too much because the AP mid or jungler may be good gankers. If you will have a hard lane against a AP solo top like or you are afraid of their jungler like or you should start with 3x .With you should have and easy time last hitting a good idea is to try to stay in a bush near the creep wave and exit only when you want to last hit so the AP solo top can't harass you as much.Unless the AP is really bad you shouldn't be able to win exchanges but if you do press the advantage and try to get a kill but remember don't push because the AP mid or jungler will come and you could die.

You should be able to get and by now and you could try to get dragon or gank another lane but never leave your tower undefended because you could lose it very fast.Of course if you can take 2 towers mid or 2 towers bot it is a good exchange one for two.Also a good exchange can be dragon for top tower but don't make it if your team isn't doing good.In the meanwhile you should try getting .I get Frozen Mallet because Sion can get kited a lot.Some may say that PD is better but i prefer the slow because champions with escape spells will still be slowed and the slow doesn't only help me it helps the people around me too.
It is almost the same but the items are different.You should try to get and . You should get .Some people might ask why not vamp scepter sooner.I buy this so late because it is better to have some MR against the enemy than having some life steal because you don't want to push. After that you should start building .

There are a lot of choices:
You could take more damage items or you could get more tanky you decide because it depends on the game.Sion doesn't need much health points because he has enough even without hp items.That is why you could get , , .You could make a lot of combination with these items it depends on you,your team and the team against you.Some times it is only the matter of personal preference.
If you would like to get more tanky you could get , . Quicksilver Sash can be used not only for the MR but also for the active because Sion can be CCed really hard.
There is also one middle item called .It gives armor,crit and a good passive which you might need.

Thank you for reading my guide on Sion and I hope that I helped you to understand him better.I might have forgotten a thing or two so please try to be understanding as possible.