your pit is decent i suppose. But ur pit heavily relies on smashes. Which is actually ur main weakness. Using his smashes over and over like that is never a good idea. Just watching u play your pit i could see it would be really predictable. Not to be mean or anything, but your arrow game is rather basic, ur fighting style has very little combo potential at best. U used a few wing stalls which is good, and the wing cancel to push lucas away was nicely timed. Ur glide approaches were rather umm not a great idea. If it were me i would have easily punished you when u tried those. U came from way too far away. and straight at him. A simple PK fire or something would have caught u. My only real advice for you is to learn how to fight without smashing aside for killing blows, at least for now. Those attacks will kill pretty well when fresh. Use some arrow loops, even if u dont intend to hit them. They will become paranoid whenever u shoot an arrow. Other stuff as well but i rather not keep rambling.
And no Tsnmi pit isnt just about ATs. His ATs are nice and everything but pit can do great with just basics and using his ability to combo. Mid to close range ownage on someone with pit will probably do alot better then and super abuse of AT's. Ats should be used to change up ur game now and then. but just constantly relying on them will make u predictable anyway.
As for the mirror shield comment before. I would say u used a bit too much mirror shield. Especially against a lucas player who didnt really PK fire all that much or ever have to really recover with pk thunder.