Zilean Runes explained
There's one set of runes for Zilean on patch 15.11 that is the clear favorite for LoL players and pros alike. The best Zilean rune paths on the position 
Mid are 
Sorcery as the primary path and 
Inspiration as the secondary path with a pick rate of 52%. Besides picking runes on Zilean you should learn how to play Zilean and if you are interested in pro matches take a look on how a pro builds Zilean. If you want to discuss 
Zilean then you should visit the champion subreddit.
Zilean runes from primary path
Sorcery empoweres abilities of Zilean and increases the available champion resources. Most of high elo players – and our LoL pros in the the major regions – have agreed that 
Summon Aery is the best keystone rune to run on Zilean. This keystone rune adds more poke damage to your abilities. And additionally grants an extra shield, whenever Zilean empowers or protects an ally with abilities. Other primary runes on Zilean are 
Manaflow Band, 
Transcendence and 
Scorch.
This is usually followed up by taking Manaflow Band for additional mana and mana regenaration. Transcendence for some more Ability Haste. Scorch increases your control in the early game.
Zilean runes from secondary path
When it comes to your secondary path, most Zilean players prefer to go with Inspiration. Inspiration opens creative opportunities on Zilean troughout the match. On the Inspiration path, the best runes for Zilean are 
Cosmic Insight and 
Biscuit Delivery.
Cosmic Insight grants summoner spell and item haste. Biscuit Delivery is a great rune for laning as it gives additional health and mana, which can help in more aggressive lanes.
FAQ for Zilean Runes
Which is the best keystone rune on Zilean?
The best keystone rune on Zilean is Summon Aery. This Zilean runes setup is then referred as Zilean Summon Aery.
What runes does Zilean use?
Runes from the paths Sorcery and Inspiration are the most used runes on Zilean. For the exact pick rates of Zilean runes used, you have to study the rune distribution presented.