Just semi high-jacking this thread since it's related to Karma, and I love Karma, but I found out I'm building karma completely "wrong" (read as different from most). Basically, I simply rush the chalice and then Spirit Visage/Sunfire Cape (based on matchup), and build super tanky with capped CDR. This allows me to have very decent AoE damage, shield on an ally of my choice, and 50% missing hp healed every so often (somewhere around 6-10s in teamfights).
I sometimes forgo Sunfire cape for an abyssal scepter if I'm mid, or precede that with philo/ss if I'm supporting, but otherwise, it seems to be a build where I can actually either grant massive utility to my team or split push and outduel nearly everyone...
Thoughts on why it'd be better/worse than a normal AP build (apart from the fact that people don't understand that even though karma has "no ult" she still can burst you down, and that yo ucan get free kills from those stupid people).