Karma Runes explained
There's one set of runes for Karma on patch 15.12 that is the clear favorite for LoL players and pros alike. The best Karma rune paths on the position 
Support are 
Sorcery as the primary path and 
Inspiration as the secondary path with a pick rate of 67%. Besides picking runes on Karma you should learn how to play Karma and if you are interested in pro matches take a look on how a pro builds Karma. If you want to discuss 
Karma then you should visit the champion subreddit.
Karma runes from primary path
Sorcery empoweres abilities of Karma and increases the available champion resources. Most of high elo players – and our LoL pros in the the major regions – have agreed that 
Arcane Comet is the best keystone rune to run on Karma. This keystone rune adds more damage to your abilities and increases your power in the laning phase. Other primary runes on Karma 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.
Karma runes from secondary path
When it comes to your secondary path, most Karma players prefer to go with Inspiration. Inspiration opens creative opportunities on Karma troughout the match. On the Inspiration path, the best runes for Karma 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 Karma Runes
Which is the best keystone rune on Karma?
The best keystone rune on Karma is Arcane Comet. This Karma runes setup is then referred as Karma Arcane Comet.
What runes does Karma use?
Runes from the paths Sorcery and Inspiration are the most used runes on Karma. For the exact pick rates of Karma runes used, you have to study the rune distribution presented.