Personally , i dont think ROB is that of a bad mu against D333.
Yes u can only use up gordo when he is recovering to the stage, but D3 doesn't need his gordo in the neutral against ROB because he outspaces him in the air.
And on the ground just dodge the projectiles and shield grab his ground moves/aerials.
You can also use up gordo when u are approaching ROB to bait him and then punish accordingly.
We aren't discussing ROB anymore. We're discussing Ness and only Ness at the moment.
So once upon a time I said I liked playing Ness, but I guess that was before I played any real Ness players hahah. So Ness gets a free 3 or 4 fairs off a hit confirm, and I find PK Fire really hard to escape as Dedede versus other characters (his large hitbox? His weight?). He also just in general has really fast aerials and an astonishing amount of kill potential for someone so small. I'm not too sure how Dedede is supposed to challenge Ness' aerials.
So, whatever you do, don't get caught in the air against Ness. Be ready to react to PK Fire and try to stay a safe distance away. PK Thunder is tough to deal with as a big body, I don't think air dodging is quite safe against it because it'll just catch you out of the dodge with the tail, which can combo back into the main part or, on the ground, into PK Thunder 2. So you know, never air dodge into Ness.
A hit off a PK Thunder can also set you up for an aerial attack from Ness and it applies good pressure on Dedede when he's trying to recover, because of how slow he moves through the air.
I mentioned this a while back, but you can cut PK Thunder 2 short with a Gordo. If Ness is forced to recover low, this is a good way to challenge his recovery.
I'd like to see what everyone else thinks, but I honestly think this is one of his hardest match-ups. The only footage I have of me playing Ness is a couple months old and not particularly good, but it's here if you want to check it out:
https://www.youtube.com/watch?v=lsifD_E2FfE
DDD can like sorta get out of PK Fire with a combination of SDI up and away and his multiple jumps.
Though, generally, Ness has already gotten to you by the time you get out of it.
Dedede can't flat out beat Ness' aerials in frame data, but they can in the sheer range of the hitboxes.
Positioning and potentially baiting out air approaches is key to putting Ness in a tough spot in the air. Retreating, full-hop fair is a good option for punishing wiffed fairs
There are a few important things to note with this match-up, and are the reasons I'd argue Ness is probably one of our better MUs among the high tiers. (And by that I mean Ness' advantage, which he probably has, isn't that great compared to others'.)
Unlike many of our other bad MUs, Ness cannot pressure you from afar when you're both on the ground. IE When we're both in the neutral and relatively even, Ness cannot force you to approach like, say, Fox or Sheik can. Ness' projectiles don't apply ground pressure as effectively. (This also makes FD a usable stage choice.) He also cannot really pressure Dedede into the air like characters like Luigi can.
What this means is that getting to our optimal position on the ground is not as tedious as other MUs. And that optimal position is really important because we
can beat Ness on the ground. Just be sure to respect Ness' superior frame data and be ready to shield or jump over stray PK Fires. Running away and then using PK Fire in the opposite direction (towards you) is a mix up to be on the look out for. Also be prepared for SH nairs when Ness is in a tough spot. It's probably his best out of shield option.
Gordos are also important in this MU. Ness doesn't have a good projectile for dealing with Gordos. Thus removing the option for Ness to easily deal with them from afar which is a big deal. (PK Thunder and Fire require too much commitment and aren't spammable in the right kind of way to do this.) Just be aware that the part of PK Fire before it's a firewall does reflect it. The firewall itself doesn't, however.
Ness' best option for reflecting Gordos is nair. This is good because it means Ness will generally look to be in the air to do just that. Since he's pretty floaty, jumping is more of an aerial commitment than, say, Fox jumping. Be on the look out for ways to potentially abuse this.
In general, don't land near Ness unless you're sure you won't get punished for your landing. There is just too much risk of getting grabbed. At about any percent you'll want to avoid getting grabbed like the plague. Usually if you aren't at B-throw kill percent, then you're at d-throw > aerial percent. This is one reason I'd personally avoid FD, just so that Dedede has more landing options. Though I don't think FD is as terrible as it is for other MUs.
This is all a combination of theory crafting based on sets I've done with pretty good Ness players (obviously no FOW or Shaky, but, you know.) and just knowing when and where Ness
will beat Dedede. I'm being pretty bare bones. Ness has more advantages than I even mentioned. There's also still off-stage talk.
Someone with with more knowledge is free to call me out on any BS I might be spewing haha