Puff main here, but I usually go Marth against Puff because pretty much everyone agrees Puff dittos are the worst MU ever, so I can talk about the MU from both sides.
One of the things I hate the most about Puff is the fact that it's essentially impossible to edgeguard her like how you would against say spacies, Sheik, etc. Unless the Puff is dumb and constantly tries landing back on stage within f-smash range, she's pretty much always going to make it back on stage either by going high or going to ledge. Although doable, it's hard to cover both options at the same time because of how much faster Puff's aerial mobility is than Marth's.
Because Marth can't edegeguard Puff reliably, and she's floaty and usually won't get comboed into a kill, Marth has a little bit of a hard time killing Puff sometimes. Marth does have a guaranteed tipper f-smash off of grabs to kill, but it's only with a
super precise pivot f-smash so very very few Marths will actually get that (
PewPewU vs. Hungrybox at Apex is the only time I've ever seen it pulled off at high level). Marth's kill options are essentially boiled down to either side-b->up-tilt (or any tipper up-tilt really) and random tipper f-smashes, which are both super telegraphed and punishable by Puff if she baits/expects it. Not so great Marth's like me will start to get antsy when Puff's at high percent and start throwing out laggy moves like these to just get the kill, which is exactly what Puff wants. Especially when she sits
just outside of tipper range and tricks you into thinking you'll hit her.
So you've just thrown out a bad f-smash and Puff is about to punish. What does she do? If she doesn't go for a bair/rest here, most likely she'll wind up tomahawking to end up right behind you. At this point, there's not really that many safe options you have here. If you manage to get a shield up in time, you're stuck. Literally all of your OOS options will either miss since you're facing away from her (up-b, grab, fair) or are just too slow and will get stuffed by up-tilt as soon as you jump (bair, dair) and lead into rest. Or she can just land facing you and either up-throw to try to trap you in the air to up-air juggle or rest you, or just f-throw/b-throw you offstage for an edgeguard. Your best bet would be to try running/WD-ing away, but Puff can still just hit you with fair/bair when you try doing that so you kind of just have to accept the damage and try to reset back to neutral. You will also most likely lose control of center stage here too, which is a big no-no for Marth but it beats getting rested at least.
This is a winning MU for Marth, but you have to be incredibly patient. As Marth, you basically just have to constantly be swatting Puff away from center stage with quick/lagless moves like rising fair and d-tilt, or up-tilt/up-air if she's above you. Many Marths aren't used to playing this kind of way (or just don't want to), and won't be able to keep it up the entire match, leading to them getting wrecked by Puff because they gave her too many openings. That's why you see Hungrybox literally never losing against Marth players, because he is easily one of the most patient Melee players and isn't afraid of dragging out matches to wear down his opponent's patience. The essence of the MU is which player can out-patient the other.
TL;DR
- You will struggle to reliably edgeguard or kill Puff, but she will have a very easy time doing it to you if you give her the opportunity.
- She has positions where you are 100% at her mercy, like directly behind your shield, directly underneath you in the air, or just offstage in general.
- In order to actually beat a Puff playing the MU correctly, you have to be comfortable with essentially camping center stage for an entire set, which 90% of Marths are not. The MU is in Marth's favor, but not really in terms of "fun."
