Hey guys I'm a Simon main currently in Gold 4. I chose not to play him in ranked however, because it would be so unfair for the enemy team to play against, as his immense skillset and powerful auto attacks are too much to deal with. Basically Simon is the best champion in existance, his passive is probably the strongest one in the game along with his extremely overpowered ultimate. However there is one problem you need to be careful of when playing Simon, and that is CC and Ignite. Often if the enemies take these spells, your damage output is greatly affected. But don't worry, you can still be a tank thanks to your extremely overpowered E passive.

Ok so the runes are just standard AD runes, I like taking these because it gives you a lot of ad at level 1 with your E, (Probably the highest in the game) making it super easy to win trades at level 1/2. Also I like to take armour seals to scale with his passive, which blocks auto attack damage up to 30 at level 1, which is also good for 1v1 scenarios at this early stage in the game. Magic resist glyphs ensure that you don't get bursted down once you get into the mid game team fights, and allow you to sustain through damage with your ult. And again the quints scale well with your E, making it easier to farm.

Ok, so the masteries are just standard 21/9/0 AD Masteries, which just help him sustain in the laning phase and mid game.

On Simon always look to max your E first as it will allow you to scale faster than every other champion in the game due to the bonus health you gain simply from farming minions. What a beautiful spell.

Next you should look to max your Q for the reduced cooldown which provides more chase potential, as you are always looking for 1v1 scenarios which you will always win in.

Finally max your W which is pretty useless unless you are playing AP sion in which case it is veeryyy overpowered.

Pros:

• Sion is very good at 1v1 scenarios.
• He is extremely powerful once he reaches level 6.
• He is a late game beast due to his E passive.
• Very good at splitpushing, due to his ultimate.
• Provides brilliant utility in team fights with his ultimate and ability to 2 shot ADC'S.
• Low cooldowns.
• Strong level 2.
• Strong laning phase if played well.
• Best splash-art in the game.
• Best skill-set in the game.
• His name is Simon.

Cons:

• Shut down by CC easily.
• Ignite rends his ult nigh on useless.
• Easily kited.
• EXTREMELY high mana costs.

Ideally you want to farm for as long as you can until your team really need you. But if they seem to be winning fights ok without you, or they aren't fighting at all, then you should always stay top and splitpush. This will draw multiple members from their team toplane and your team can then focus on gaining other objectives such as dragon and towers/inhibitors. Use your ult to splitpush if you want to, it gives you crazy attack speed. But this leaves you vulnerable when people come to stop you. It's a risk I always take however and most of the time I am still able to kill at least 2/3 members in a 1v3 scenario, once I have achieved 2 items.
(Hydra, and Botrk).

In summary Sion is the best champion in the game basically.
He is a very skillful character with a lot of potential. I'm looking forward to seeing him in the LCS any day soon.

Some final tips to sum up completely:

You should just kill everyone the whole game with his amazing utility and skillset. This will make their team very angry and you will always win the game 100%.
GGWP EZ.