I did notice that corrupting potion caught my eye, why are you running that instead of something like hunters?

AP Quints do seem like a better option, but what about penetration? Karma needs it. Sure, you will eventually buy Sorcerer's Shoes and Liandry's Torment, but the extra 6.08 magic pen helps, along with the 8.something armor pen.
You could get rid of the Attack Speed marks, but that will just make her jungle clear slow. Karma's attack speed at level 1 is .625. Adding 10% may not seem like a lot, but it does help.
Her ganks are fine, especially with the CC she has. You can speed up your teammate while you are slowing and trying to root the enemy.
The rune set tries to make the most of out Karma's mantra, along with her mid and late game power. Her early game isn't the greatest. Or at least I don't think it is.

This build, in my opinion, makes Karma a fighter and a mage.

I can't help but feel that the hybrid pen runes, while great in lane, make your jungling life harder than it needs to be.

Attack speed marks would help speed up your clear with not just more autos, but mantra would be up faster. Hybrid pen quints are a cool idea, but Ap quints would allow you to go through the jungle faster and make your ganks a bit more impactful.