Vs. RX - I don't really recommend just riding your bike offstage, b/c someone could chase you down and gimp you for doing so. It's safer to just eat it or throw it, imo. Something I really really like against MKs (and anyone really) that works incredibly well is using invincibility frames from the edge to hurt them while they're offstage. If you snap the ledge and quickly drop and jump, you can hit them with an invincible backair, often netting you an early kill, or at least damage, and you can repeat the process. If they try to approach from below, invincible wafts = god.
Terrible farting for the most part, but we all have rounds like that
Make it a habit to just always hold up against MK as you're getting hit to help you DI. This'll make it so pretty much the only thing that can kill you is a grounded shuttle loop.
Vs. Red RD1 - Very patient playing, which is good. MK is one of the few characters where following up with pressure combos isn't exactly advisable as he can get out of them with b/c of his light weight and super fast aerials (Corrupted, dair > dair > upair is only guaranteed on heavies. If they DI, MK and GWs and others can get out of it). You could've grabbed more, but your poke game was solid. Super desperate to land that fsmash on his second stock, he took of your entire stock b/c of it. Just keep poking and playing safe and eventually you'll kill him. Getting desperate = getting predictable.
Red RD 2 - Some desperate Fsmashing again. If the MK starts spamming nair like Red was doing. Run up and shield, you'll have plenty of time to grab his nair on your shield. IF they're edgeguarding right next to the edge, consider either biking really high, or biking really low to get around it (I've actually biked UNDER a stage, and then DI'd around the edge to get back on when an MK is being dumb).
Red RD 3 - Bfield again
Lol, how you lost your first stock XD Much better performance, but I got the feeling that you were doing better here b/c you started figuring him out, above all else XD He always falls for that waft on the bike apparently.
VS. MK in general - more neutral airs. Wario's nair is ****ing amazing, use it moar. Not only does a sh nair go over their dsmash, the weak hit combos into guaranteed grabs, and if it trips it's a guaranteed fsmash. Stop going to heavily platformed stages that aren't Brinstar/Green Greens, lol.