Sion Runes explained
There's one set of runes for Sion on patch 14.12 that is the clear favorite for LoL players and pros alike. The best Sion rune paths on the position 
Top are 
Resolve as the primary path and 
Inspiration as the secondary path with a pick rate of 74%. Besides picking runes on Sion you should learn how to play Sion and if you are interested in pro matches take a look on how a pro builds Sion. If you want to discuss 
Sion then you should visit the champion subreddit.
Sion runes from primary path
Resolve empowers the survivability of Sion and increases the tankiness. Most of high elo players – and our LoL pros in the the major regions – have agreed that 
Grasp of the Undying is the best keystone rune to run on Sion. This keystone rune gives Sion alot of sustain and helps to force your opposing champion out of the lane. Other primary runes on Sion are 
Demolish, 
Conditioning and 
Overgrowth.
Demolish increases your pressure on the enemy turrets. This rune will help you to punish bad roams or backtimings of your lane opponent. Conditioning powers up Sion tankiness after the laning phase. Overgrowth increases your maximum amount of health.
Sion runes from secondary path
When it comes to your secondary path, most Sion players prefer to go with Inspiration. Inspiration opens creative opportunities on Sion troughout the match. On the Inspiration path, the best runes for Sion are 
Biscuit Delivery and 
Cosmic Insight.
Biscuit Delivery is a great rune for laning as it gives additional health and mana, which can help in more aggressive lanes. Cosmic Insight grants summoner spell and item haste.
FAQ for Sion Runes
Which is the best keystone rune on Sion?
The best keystone rune on Sion is Grasp of the Undying. This Sion runes setup is then referred as Sion Grasp of the Undying.
What runes does Sion use?
Runes from the paths Resolve and Inspiration are the most used runes on Sion. For the exact pick rates of Sion runes used, you have to study the rune distribution presented.