I just throw LeiFang regularly. Christie seems most annoying. Ayane's really not that bad if you can stay at the right range. Dunno bout Sarah. 3P can probably troll her.
@Yurlungur The best way I've found to take out Genfu is by looking hard for whiff punish, and keeping my distance. It's not easy to use Ein but he has a lot of moves to keep Genfu away from him.
Of course I'm talking basic Fu and not Sweet Revenge Fu.
Ayane vs genfu isn't really that bad for Ayane as people think. It's a tough match up but I don't really believe it to be her worst anymore. Only characters in this game that give her problems are genfu and Leifang (and herself if you want to count the mirror) but she, like genfu and Leifang, have no "worst matchups".
If the lei fang isn't smart with the sabaki's then you don't have to worry