It has a weakness. You can perfectly space an F-smash right into him if he misses you. Its also not too hard to smash DI out of it to avoid most of it. Just hit up during every hit and if you do it right and lag doesn't interfere it should just smack you away from it before the final hit. If Dedede's fat ass can smash DI out of it, Marth should have no problem at all. Almost every Pikachu uses it for damage and out of shield. The ones that don't probably don't know much =p If anything I'd say Thunder is far worse then Down Smash ^^;
Theres a reason why Pikachu is usually speculated to be low mid tier =p He doesn't do well in tournaments on his own either.
My Creations in Modnation Racers! Check zhem!
http://community.modnation.com/en-us/players/IvoYaridovich/creations
