I find myself running shadow claw more than shadow sneak simply because I would rather tank the hit in shield form and attack after than risk the opponent surviving and taking out Aigeslash. I realize that the main reason to run shadow sneak is so Aige can take on Mega Gengar. I believe you would be better off simply having another counter to MegaGar. Aige loses a lot when he opts for ss over sc. Whenever I hear others talking about how they beat Aige, they always seem to mention that it was because they could tank ss. I like to see Aige as more of a defensive tank that just so happens to be able to kill things rather than a ho sweeper.