The Mario matchup for us (or for me at least) is worse than cancer.
Mario can just combo us into oblivion with anything he pleases. That and fireballs really hurt sometimes. Any Mario main would probably chuck fire at us from a fairly close range anyway if he plays aggressively, which is a large part of Mario's neutral anyway. Thus we have to be in the air for most of the fight, but Mario's air game is superior thanks to his n-air, b-air, and u-air. That, and unlike in most other matchups, where we can mix up our recovery with safety, our recovery is very unsafe against Mario. Recover horizontally? Caped. Recover below? B-air spiked. Mangle? I think this one speaks for itself.
Though we can fight on FD with fair safety, however. Pit's arrows are versatile enough to be used in air and not get punished with the cape. However, I wouldn't even bother playing Dark Pit against a Mario because arrows pretty much go straight and electroshock can have trouble effectively killing Mario thanks to his amazing air speed and medium weight, despite its early kill power. Though we can combo him pretty well and rack up a good 20% with a basic combo out of d-throw. It's not like Luigi where Pit has to be in the air to combo him at all. That, and our f-air, despite it's startup, is pretty effective against Mario's recovery. That, and Mario can have trouble landing, and that's where our u-smash and u-airs come in.
Overall:
(40:60)
(30:70)