I actually think karma looks incredibly strong right now.. Has nobody else considered that she has got an aoe speed buff and shield at level 1? that lends itself to incredible level 1 engages - she can go for aoe damage and a 50% aoe slow if the speed buff isn't necessary, that's amazingly powerful for level 1.
In terms of damage, shes no syndra but her ratios are strong, shes got shortish cooldowns and would benefit for cdr even more and so i can see builds like athenes, morellos, rylais, deathcap being extremely powerful(40% cdr, 436ap) (on mid karma obviously). Alternatively twin shadows would work well with her w allowing her the root, for a more support karma. She has some scary versatility.