I feel like I may have seen this idea on another user blog, but whatever. Here's a simple idea for a Karma rework. Her main problem seems to be her long mantra cooldown, and the fact that she can't do much with her non-mantra'd abilities. So, having a stance-based ultimate and dividing her damage and support to the different stances lets her keep a similar playstyle, but lets her be a passive or an aggressive support at will. The stat bonuses on her ult simply let her be less item dependent.
Obviously all values are just conjecture (there's no way for me to balance them).
Edit: Just for clarity, my idea was that her different skillsets would have separate cooldowns, so she could quickly cast all her Yin skills and then switch to Yang and keep casting, or vice versa.
Edit 2: Posts have been made on the League forums and League subreddit. It would be awesome if this idea gained some traction and got seen by a Rioter.