[Valkyrie Quicksand] is a new valkyrie in v6.5. See my main guide:Valkyrie Quicksand Guide
Now, I'd like to go over her gear options, for herself and her supports. It's more complex than it seems!
So, without further ado, let's begin!
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[Valkyrie Quicksand]'s Signature Gears
First, I'd like to introduce the new [Aladdin] stigmata and [Twirling Glaze], the chakram.
This gear is [Valkyrie Quicksand]'s signature gear, and it is by far her best choice.
All of this gear will be available during the first 4 weeks of the v6.5 update, with a discounted hard pity.
If you're going to get it, get it now!
[Twirling Glaze: Lustrous Bloom]
This is the PRI-ARM version of the chakram.

The appearance of the chakram~

The ATK and CRT values of the chakram~!

Extra effects on Weapon Active

Passive damage bonuses!

Even more passive damage bonuses!
As you can see, this chakram has many bonuses related to bleed DMG, and many effects specific to [Valkyrie Quicksand].
This makes this chakram work very well with her, and it performs far better than any other.
[Aladdin]
This stigmata is similar to [Twirling Glaze] in that it is made for [Valkyrie Quicksand].
It will perform the best out of any stigmata, and even has some use outside of her own equipment (which I'll discuss in a bit).

Aladdin (T) art.

Aladdin (T) effects.
This stigmata is very effective for [Valkyrie Quicksand], as her ultimate deals a large amount of bleed DMG.

Aladdin (M) art.

Aladdin (M) effects.
This stigmata increases DMG dealt from the whole team against bleeding enemies, which makes it particularly effective.
Not only does [Valkyrie Quicksand] deal extra damage, but so does [Starry Impression]!

Aladdin (B) art.

Aladdin (B) effects.
This stigmata is the strongest of the three (although you should use all three regardless). Not only does it increase your own damage, but also makes enemies TAKE more bleed DMG, which means it again affects [Starry Impression]'s damage!

2- and 3-piece effects of Aladdin.
These set bonus effects are incredibly potent. The 2-piece effect is especially effective, but the 3-piece also regenerates SP for the holder, which is needed for [Valkyrie Quicksand].
All in all, this gear is very strong for [Valkyrie Quicksand], and is even discounted right now!
It's certainly a very good thing to spend your Crystal on.
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Other Options
Not everyone can or will pull [Aladdin] and [Twirling Glaze], so what are the next best options for these players?
Well, it turns out that there are quite a few good craftable stigmata for [Valkyrie Quicksand].
Chakram options are a bit more limited, but there are some options that aren't too bad if you already have them.
Weapons
This section will be very brief.
The best option is obviously [Twirling Glaze].
After that, it goes like this:
Purana Phantasma: ~84%
Rudder in Dream: ~78%
Lost Conviction: ~75%
Gilded Librae (lv50): ~68%
Ring Blades: ~62%
(weapons were tested lv65 if they had a PRI, lv50 if not, or lv25 if 3*)
Something to note about this ranking: DO NOT craft Gilded Librae just for [Valkyrie Quicksand].
As you can see, Ring Blades is really isn't that much worse when you're already that far behind, and you'd be throwing away Honkai Shards to craft and upgrade Gilded Librae.
If you have Purana Phantasma, though, then obviously just use that.
Stigmata

Forgive the bland look~
All dmg was tested with the standard rotation from my main guide.
HoS: S0, DoS, 1416 ATK, Tesla Band T + Aladdin MB
SI: SSS 1394 ATK, full Cezanne
This graph shows the relative performances of different sets of stigmata. As you can see, Aladdin (TMB) is the best performance.
On top of that, it also regenerates SP, so it has that advantage over many of these other sets too.
Here’s a few notable mentions:
Dracula T Shuijing MB:
This set is fully craftable! It is [Valkyrie Quicksand]’s best budget option.
It is still considerably worse, but “worse” in this case is still only a little bit worse than many other DPS units in the game because [Valkyrie Quicksand] has so much damage to begin with, and may still work well enough on her weathers.
Since the valkyrie herself is farmable, if you don’t pull her gears, this is the thing to craft.
Elysia MB also deserves the mention, in case you don’t want to craft Shuijing just for [Valkyrie Quicksand] and you’ve already crafted Elysia.
Dracula T Dirac MB:
This set is fairly bad most of the time, but it may have some niche uses, as it gives extra SP regeneration to the user.
It makes the valkyrie’s damage heavily reliant on Ultimate, which [Valkyrie Quicksand] doesn’t always want to do, but it is notable enough to put on this list.
Aladdin TB PPM (aka Mei: Beach Party (M))
This set looks like it’s almost the full effects of the full set! Wonderful, I don’t have to pull the full-
Hold on right there, there are a few conditions and other things it lacks.
The most important is that the 3-piece Aladdin set gives SP regeneration, which is very important.
Second, in rotations where you are not using your Ultimate or are delaying its use due to a problem with SP, PPM will no longer line up well with your damage and it will likely be far worse.
Also, HoS is using Aladdin MB in these tests. Aladdin M being on another party member may be diluting that damage bonus from [Valkyrie Quicksand]'s own equipment, so without that, PPM may be much worse than shown in this damage test.
Be wary of raw DMG numbers~
There may also be other sets with gacha gear (I think I saw people trying Bianka Theater TM Newton B, although it didn’t seem that impressive to me) that are up on this list, but this is the list that will be most useful to most people.
If you're coping hard enough that you don't have ANY of these options, keep in mind this passive:

"Mystical Nights" passive~
This means that any stigmata bonuses that mention ranged, melee, or crit DMG do not work.
Normal Physical bonuses do, though.
Now, let’s begin with her supports~
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Support Gears
Now that we have gear settled on [Valkyrie Quicksand] herself, let's talk about what her supports need.
As covered in my main guide for [Valkyrie Quicksand], her best supports are [Herrscher of Sentience] and [Starry Impression], and using anyone but those two will result in significantly lower damage.
[Starry Impression]'s gear is actually simple - have Cezanne or you'll do a lot worse.
Other options:
Holmes TB PPM: 80% (requires some timing)
Gluttony T PPM Newton B (GPN): 79% (requires some timing)
Holmes TMB: 77%
Keep in mind you cannot double up on any of these stigmata - if HoS is using Holmes or PPM or Newton (or VQ for that matter), then you can't use it on a second character on the team, as it doesn't stack.
So, why isn't it simple for HoS?
The reason for this is the same "Mystical Nights" passive from above.

Don't you love seeing this again~?
HoS's signature stigmata, Shattered Swords, primarily gives buffs to team Crit Rate and Crit DMG.
This means it doesn't provide very much support to [Valkyrie Quicksand], and so there are other things we have to use.
Here's a test of the notable ones:

Again, sorry for the bland look~
As you can see, using Aladdin (MB) is actually the best choice, because all of its buffs can stack and benefit the whole team.
This increases both [Valkyrie Quicksand] and [Starry Impression]'s damage, so it's very valuable.
Notes
Any time this chart uses TBand T, you can also use Gluttony T.
This will likely result in slightly higher damage, but it's less consistent as you have to pick up the candies.
For any Shuijing combination, you have to QTE in on HoS - the easiest way to do this is to use Griseo's Combo ATK right after her Ultimate. This does mean that it will take slightly longer to do the rotation, though.
Using Aladdin MB on HoS is of course the best option for raw damage (sometimes TB + Paga M for shieldbreak), but that does not mean it's necessary. Even without that, [Valkyrie Quicksand] still has plenty of damage, and most of the time will not need it.
Also, most people are not pulling an extra set of Aladdin, and it's likely not worth it for you. You'll do just fine without it, so don't worry too hard.
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Conclusions
Compared to many other Valkyries, [Valkyrie Quicksand] has fairly good options for cope gear.
Pulling her own gear is definitely a good choice, especially with the discount, but in RL and below, you probably won't need Aladdin at all unless you want to get top 3 in your bracket.
In the end, it's up to you. Spend your crystals wisely, Captain~!
Message Merp#6832 on Discord with any questions.
Thanks for reading~

