No amount of help will let you beat a MK that knows what they're doing.
General help includes:
Do as little as possible. He can punish pretty much everything, so try to never commit.
If he's gliding at you, Bair. It beats the Glair and then you hit him. All other options against Glide suck.
Practice that CG > Usmash. Learn how to time it to slide under platforms like on BF or PS1.
Recoverywise, I prefer recovering mid to low. MK ***** our landings from up high. If you're caught above the stage with no jump and can't get down, just Down B to the stage to regain a jump and your eggs.
We can't gimp him. Just throw eggs.
We can't punish any smart tornadoes on our shield. Just regain stage control when he stops. The only real way for us to punish Tornado is to beat it out directly. Usmash/Pivot grab are your tools for this.
Egg Lay to cover your landings is a must.
Stay EXTREMELY patient. Also keep from getting frustrated. I've pretty much lost my ability to stop getting frustrated against this character because he's so broken and safe it pisses me off to no extent.
If there's any specific stuff feel free to ask. I feel like these are some good tricks to know, though. And remember, in order to beat MK, you'll have had to massively outplay him. Even if you do, you can still lose cuz MK da bess.
Also, guys, if Celes and I disappear, we died in the hurricane.