Okay, I should be working on my paper, but I have eight hours to work on it, so here's my advice for Ganondorf against Marth!
Try not to dash attack. It's easily punishable and almost never your best option. Use JC grabs instead, they'll set up much better, especially against Marth.
You're kinda predictable on your approach. Dash dance a little, mix it up. Space fairs and you won't get grabbed. Try to shffl, too, you're using double jumps to approach way too much.
I know it's not easy to recover as Ganondorf, but you should at least attempt to go as close to the edge as possible. And learn to ledgetech. That's good too.
Don't roll every time you grab the edge. It's really really predictable. Just in general, you don't really mix things up at all, and if your opponent figures out your patterns, you're absolutely screwed.
Also, lightshield edgehog Marth. No reason not to. If he goes high to try to avoid it, reverse uair him. Currently your edgeguarding game is haphazard at best.
...stop Wizard Footing off the stage. Especially against Marth. Seriously.
Don't roll so much. You can get punished really badly for doing it too much, because it's not that hard to chase down, especially if your opponent is expecting it.
The airdodge recovery is good every once in a while, but you're doing it far too predictably. All your opponent has to do is bait it out and then charge an fsmash at you.
You're missing a lot of L-cancels. So work on that. Also, learn to DI better.
Try to find better opponents so you're forced to improve. It's much harder to get better when easier things work.
