IMO this one should take Sheik into account, since the majority of Zelda players will use Sheik for damage, and switch to Zelda when you're at a high %.
Zelda's scary when you're 90+%.
I played against RyokoYaksa (Sheik/Zelda extraordinaire) via wifi (green connection). I noticed a bit of trouble concerning Sheik that I'll mention if we do a Sheik matchup/combined one here. But vs Zelda, I seriously just suck at dealing with Usmashes. lol don't get caught by the invincibility transformation bait (Sheik dies> respawns and immediately transforms to Zelda and catches you with Usmash if you try to hit cause she still has invincibility frames XD). I did see some interesting moves that I haven't seen other Zelda people use.
It's not an impossible matchup, but most of my wins were done via taking advantage of player habits, like dodge or recovery, rather than outmanuevering Zelda's moves, which points towards an advantage for Zelda (and IMO it's a major one, considering Zelda generally only appears as the angel of death when you're almost dead).
Her kill moves are... well... sweetspot B-air/F-air/U-air/U-tilt/Dsmash (somewhat rare)/U-smash (somewhat popular). Isn't that a pain in the butt?
vs Moves-------
Din's Fire isn't too bad, I mean, anything that covers you with an attack box (hint, any aerials, ASC, even spindash roll, if you wanna clangcancel it into a dash move) will protect you from the fire.
Her F-smash is actually kinda tough to punish from the ground, and it's somewhat spammable, so don't be caught off guard by a followup. It's a bit like Lucario's Fsmash, except it's multi-hit, and you better take this into consideration.*
U-smash can be done sliding (not sure if it's out of a dash or DAC'd, but I see Zeldas use it), so don't be too sloppy when you're close to her.
However, you can hit Zelda from the front (not sure about back??, or maybe it was the other way) with a spincharge during her Usmash, if you want a counteraerial setup, or F/D-tilt for disruption. It has a freakish reach and can catch you out of an aerial or even a dash. Think of it like Sonic's U-smash, but with much more launch power and reach.
On a silly note, falling springs will clang-cancel the U-smash, if you have some strategic use in mind.
U-tilt is much faster, but single hit. It doesn't have the range nor power of Snake's U-tilt, however, it still kills pretty darn early (low 100s?), so don't just think she has U-smash.
D-tilt is sometimes used as a tripper/'lock', and if you're sloppy by the edges, a meteor as well. Sets up for smashes, so watch out for it.
Nayru's Love - Zelda's neutral B, has invincibility frames and lingering attackbox, so you can't immediately grab her out of it. You might be able to hit her from the top, but trying to hit her from the sides is a no-go. This will be used to stop your momentum, especially when you try to punish something like (what you think might be) landing/move lag with a grab.
Aerials: N-air is like Ness' where it will stop you. Her other aerials are used for killing, and just assume that you're playing a good Zelda who will space well and do absurd things like nail a sweetspot Lightning kick right before she lands.
You might never worry about U-air, but be warned, it has freakish reach. I was standing about 2-3 character distances from the edge on Final Destination (spaced to "tip" a possible ledge getup/attack with Sonic's Fsmash) and I got nailed with a U-air from under the lip in FD.
*I have a bad habit of trying to pshield moves. It sounds like a good thing, but normally, when I'm in the pshield mindset, I let go of shield right away so I can attack or something right away. However, this is not true for Zelda. Hold shield for the duration of the attack, and if you can, dodge the last part of Fsmash/Usmash. If your shield gets eaten, run away for a bit.
I need more matchup experience with good Zeldas ;__;