Hey all,
I've been playing Karma in the midlane ever since I came back to League at the very end of S7.
Sorry that this is a ****py Build guide but I've tried to give you the essentials.
Every pick that is not marked on the chart above is easy to lane against and not a real threat.


Update: 8.23 is live and all I can say is I hate dark harvest. GL boys, next season should be good for Karma:)
Update: 9.10 Rune changes and meta shifts often call for tankier Karma builds that focus on utility a bit more than before. I still believe that stacking mana and CDR is one of the best ways to scale this champion

Pros:
- Great kiting ability
- Tons of damage late game
- Good utility

Cons:
- One of the weakest midgame champions and people WILL abuse that
- lack of immidiate hard cc (w takes 1.5 sec)
- W has one of the longest cast animations in the game which means it fails to cast sometimes
- Limited mobility (no dashes)

The only skill that's useful for farming is Karma's Q ability. It's great aoe, and if placed correctly you can hit upwards of 10+minions with it.

While using this ability for farming, it's also a good way to poke by using the enemy minions to trigger the splash.

The three best options to get together with flash are Barrier, TP or Ignite.
Against champions with high burst I ALWAYS take barrier.
If your lane favours you, you want to take Ignite or TP depending on whether you want better lane control or more kill potential

I feel like I need to dedicate a special "chapter" to my thoughts about these 2 runes:
With the recent changes (8.16) to Aery, its early game damage was nerfed and its late game was already not too great. Also with a 75-80% hit rate on comet(thanks to Q and RQ slow), aery gets outscaled by it by quite a bit(comet deals about twice as much dmg).
Since this is a solo lane guide, the shielding part of the Aery is pretty much useless the first half of the game, which means that you are basically handicapping yourself early, so that you can have a minimal advantage in the shielding and a big damage disadvantage.
Since this guide pretty much tells you "Get max cdr and then build magic pen and pure AP", your shield is going to be great anyway, so the extra 100-150 shield, which doesn't work on you anyway is not really important.
Furthermore, your E is a great engage tool so when your adc is not getting jumped on by 4 people, you will be using the shield on yourself to better aim your RQ combos and to negate damage, which again doesn't speak well for the aery.