Yup, reverse glidetoss to Fsmash covers like a 3rd of Final Destination.
Anyway, the problem with Diddy is that he racks up damage easily. Glidetossing bananas at you, to dash attack to another glidetoss gets you up in the percents easily. He's forcing you to get offstage, as he knows that you aren't one of those characters with amazing options at the ledge. From there he'll try to gimp you. It's simple right? But it works.
His recovery is not really easily gimped as you may think. A good Diddy will almost never get gimped to be honest.
Also, if you Counter his Up+B, it blows up in your face to if you aren't spaced far away enough from it. So be careful.
Anyway, you're kinda forced to an aerial approach here. You can SHAD airdodge sometimes and it works well as it can catch bananas and you can avoid a follow-up or two if you don't overdo it and force the Diddy player to out-predict you. But for the most part, playing Melee Marth against Diddy isn't out of the question. You'll be doing a lot of aerials that's for sure. At later percents, a fresh Fsmash even untipped gives you some breathing room and a chance to edgeguard.
As for Dancing Blade, if he manages to shield it, it seems Side, Neutral/Down, Down, Up stabs through his shield. I'll have to do more testing. If it's tipped, you can stop at the first one and get out. If you roll though, chances are he'll chase you. It's a prediction game, your best option theoretically might not be the one you would want to take.
The problem I have with pro Diddy players is that it's so hard to seize back control of the stage. They read you as well as you try to read them (well, better actually), but they have some many options with the bananas and lagless attacks; more than you. Than don't even have to try to kill you. They rack up damage so well that you'll die eventually anyway. It's frustrating, and it's hard to kill a good Diddy since you have no safe-on-block kill moves.
