Karmas are energy based organisms, they eat a diet of candies and milkshakes, their strong point is speed the reason builds you find lack the aoes is because they are simply worse than going full dps(damage per second).
http://www.dbocom.com/tools/skill-ca...5005100564110/ when lvling i would max serene focus and lose the points from hesitation.
for gear I would go for a mixture of con and focus although lp% is always worthy of a mention tends to be harder to get hold of though as every ultimate from here to timbuktu wants lp%.