ADHD
Smash Hero
Diddy has several options for not getting back on the stage and in control, I gaurantee this will instantly improve your mk matchup or any other character that limits the air well. First I'll start with the obvious things.
Air-dodge:
This is self-explanatory. Diddy's airdodge is quite good, but most better players will bait it out and punish it. Only use it if you feel you must, otherwise don't bother it's dangerous. Choosing what direction to DI while airdodging also takes sense and reaction to what they are doing at that very moment. Metaknight will eat you alive if you spam airdodge.
Side B/Reverse peanut gun cancel retreat:
So the side b is pretty obvious why it's good, if you are trying to get back onto the ground and they are directly under you baiting out some kind of mistake or charging a smash, just side b away and problem solved. The peanut gun canceling does a similar thing just not on the level of the side b. However, for the reverse peanut gun cancel to work you must be going at full speed left or right before you turn it around to get the momentum boost. It will give you a slight push, at least out of range to get hit with an average-sized smash. The bonus to this is that you still have your side b if you reverse peanut gun cancel, so if they chase you right after then you can side b and **** their face! A great option with the RPGC is when you're DI'ing back onstage over the ledge is to use it to then reverse momentum in the other direction and fall down grabbing it.
The FAIR:
If god were to kick something, it would be as powerful as diddy's fair. This aerial is so ****ing good. It's the best mix-up to be unpredictable with, because of it's priority it will most oftenly beat out other opponent's aerials/always clash with them. If you're offstage high up in the air and coming back down while metaknight is trying to be gay and hit you with something, just fair his face. It will make them more cautious about gimping you and I gaurantee you will get back onstage without taking as much damage if you use this against him. Just be careful, their nair will clash with it and it will kill you at high percents if you attempt this. Also in the same situation for using the side b (if they are directly under you on the ground or slightly in the air) you can just fast fall and fair their face. It can't be shieldgrabbed with good spacing, but they can still release their shield and dash grab to punish the lag. Just be careful about it and use your smarts when using this aerial.
Nair:
Shut up guys, this aerial sucks so bad and stop overrating it; but it does have some minor use in getting back down to the ground. Because of it's freakishly long-lasting hit box, if someone is trying to bait an airdodge and they're under you you can just nair them and the weaker hit will sometimes pop them up. It will even clash with characters who have small range, like pikachu or a metaknight's crappy-spaced uair. It's risky, but sometimes worth it.
Dair (yes, dair):
I can't tell you how many times people try to approach me from below in the air thinking I have no options for hitting them vertically. This is situational as hell, but sometimes the dair will just spike them lol. Yes it has landing lag, but they won't expect it to have happend and not react fast enough if ever to punish it. Don't try to use this against some uair with massive range like ZSS's uair for example, it's better vs falco because it will clash with his.
Gimp-prevention recovery tactics:
If you ever have played a really good lucario, marth, metaknight, or kirby you will notice yourself sometimes getting frustrated while trying to recover. If you mix up the order of when you jump, or side b it can help... but not so much. If you are mid-height above the stage trying to recover, you can just flip kick. Since it has so much priority it will either hit them away and you'll get back onstage safely, or it will clash with their aerial. The general idea however though is to just side b AWAY from the stage and then charge your barrels. You can either aim your barrels to the ledge or so you land in the center of the stage. It risks being punished either way but it really doesn't matter because the punishments won't be bad at all. Just DI the smash or grab if you are punished while landing in the center of the stage. The final thing I will say about recovering is if you have good DI and you are knocked into the upper KO zone corner of the screen and survive, you can reverse peanut gun charge (don't cancel it.) Charge it all the way up and then release it to get a decent boost towards the stage, and then side b. I wouldn't suggest attempting to side b grab people offstage, because they have learned from me and will always just aerial it away. Side b only as a last resort or if you need to, otherwise DON'T and just charge your barrels.
I believe that's all Long read, sorry if it's boring.
Air-dodge:
This is self-explanatory. Diddy's airdodge is quite good, but most better players will bait it out and punish it. Only use it if you feel you must, otherwise don't bother it's dangerous. Choosing what direction to DI while airdodging also takes sense and reaction to what they are doing at that very moment. Metaknight will eat you alive if you spam airdodge.
Side B/Reverse peanut gun cancel retreat:
So the side b is pretty obvious why it's good, if you are trying to get back onto the ground and they are directly under you baiting out some kind of mistake or charging a smash, just side b away and problem solved. The peanut gun canceling does a similar thing just not on the level of the side b. However, for the reverse peanut gun cancel to work you must be going at full speed left or right before you turn it around to get the momentum boost. It will give you a slight push, at least out of range to get hit with an average-sized smash. The bonus to this is that you still have your side b if you reverse peanut gun cancel, so if they chase you right after then you can side b and **** their face! A great option with the RPGC is when you're DI'ing back onstage over the ledge is to use it to then reverse momentum in the other direction and fall down grabbing it.
The FAIR:
If god were to kick something, it would be as powerful as diddy's fair. This aerial is so ****ing good. It's the best mix-up to be unpredictable with, because of it's priority it will most oftenly beat out other opponent's aerials/always clash with them. If you're offstage high up in the air and coming back down while metaknight is trying to be gay and hit you with something, just fair his face. It will make them more cautious about gimping you and I gaurantee you will get back onstage without taking as much damage if you use this against him. Just be careful, their nair will clash with it and it will kill you at high percents if you attempt this. Also in the same situation for using the side b (if they are directly under you on the ground or slightly in the air) you can just fast fall and fair their face. It can't be shieldgrabbed with good spacing, but they can still release their shield and dash grab to punish the lag. Just be careful about it and use your smarts when using this aerial.
Nair:
Shut up guys, this aerial sucks so bad and stop overrating it; but it does have some minor use in getting back down to the ground. Because of it's freakishly long-lasting hit box, if someone is trying to bait an airdodge and they're under you you can just nair them and the weaker hit will sometimes pop them up. It will even clash with characters who have small range, like pikachu or a metaknight's crappy-spaced uair. It's risky, but sometimes worth it.
Dair (yes, dair):
I can't tell you how many times people try to approach me from below in the air thinking I have no options for hitting them vertically. This is situational as hell, but sometimes the dair will just spike them lol. Yes it has landing lag, but they won't expect it to have happend and not react fast enough if ever to punish it. Don't try to use this against some uair with massive range like ZSS's uair for example, it's better vs falco because it will clash with his.
Gimp-prevention recovery tactics:
If you ever have played a really good lucario, marth, metaknight, or kirby you will notice yourself sometimes getting frustrated while trying to recover. If you mix up the order of when you jump, or side b it can help... but not so much. If you are mid-height above the stage trying to recover, you can just flip kick. Since it has so much priority it will either hit them away and you'll get back onstage safely, or it will clash with their aerial. The general idea however though is to just side b AWAY from the stage and then charge your barrels. You can either aim your barrels to the ledge or so you land in the center of the stage. It risks being punished either way but it really doesn't matter because the punishments won't be bad at all. Just DI the smash or grab if you are punished while landing in the center of the stage. The final thing I will say about recovering is if you have good DI and you are knocked into the upper KO zone corner of the screen and survive, you can reverse peanut gun charge (don't cancel it.) Charge it all the way up and then release it to get a decent boost towards the stage, and then side b. I wouldn't suggest attempting to side b grab people offstage, because they have learned from me and will always just aerial it away. Side b only as a last resort or if you need to, otherwise DON'T and just charge your barrels.
I believe that's all Long read, sorry if it's boring.