Keep/Change/Delete

[Camille]

Keep, it is useful for stopping Taunt and Encore.
Powder

 

[Lone_Garurumon]

Up the power, 50% HP or bust. A move that demands this level of hard-read needs way more payoff to be worth the moveslot investment. Especially since, even in a closed-sheet system, it's not the kind of scenario that a player's going to blunder into twice. You get one free shot and everything after that takes hard-reading that needs more payoff to be worth it.

Surging Strikes

 

[Camille]

Keep, I guess.
Parental Bond

 

[Lone_Garurumon]

The damage-reduction in Gen 7 was nice, but I think the biggest thing to help balance it is just to only trigger secondary effects once. As I recall that was really the main thing that made the ability as insane as it was. I feel like it'd end up a lot more reasonable if the little bit of bonus damage was all it had, since that's still very impactful in several aspects.

Sky Attack

 

[Camille]

Keep, it may not be the most practical move, but it is still iconic.
Alluring Voice

 

[Okido]

Keep? I feel like inflicting confusion only if the target has raised their stats in the same turn is a very hard read for not much payoff, especially when it's a move mostly learned by support/healer Pokémon. But buffing it doesn't really seem like the right choice here either, so I guess it's fine as is.

Brine

 

[Sheep]

Keep until I get a better move. It hasn't let me down in earlier parts of the games!

Play Rough

 

[Pasio]

Make it 100% accuracy pls, that would be lovely. Great move. There's not many great physical fairy-type moves out there and I tend to use this move a ton where I play. It deserves 100% accuracy and can have that high without any repercussions.

Thousand Arrows

 

[CyanLaser]

I’d keep it. It’s unique in that it can hit Flying types as a Ground attack, doesn’t have too much BP or an annoying sub-100% accuracy, and it’s not like it renders the Flying type useless on Pokemon like Zapdos either, since all hits against Flying types will be neutral. Plus, Zygarde deserves a unique move like this one after not having any presence in XY and still not getting to shine in SM’s plot.

Thief

 

[CatExe]

I'd make it like Knock Off, where it does double damage if it steals an item.

Defeatist

 

[Lone_Garurumon]

Keep but give Archeops a second ability, whether standard or Hidden. I really do like the flavour that Defeatist brings to Arhceops' character, but it'd be nice to actually be able to, y'know, use that thing.

Pluck

 

[Okido]

Keep as is. It's decent as an early-game move in singleplayer, and I'm sure you could find a niche use for it in competitive.

Loaded Dice

 

[Stef50S]

Keep
It's a cool item that gives more incentive to use multi-hit moves without being a straight up Skill Link clone. Now all we need is more consistency between the accuracy and base power of multi-hit moves.

For example, Fury Swipes

 

[Camille]

Maybe raise the accuracy, as it is unreliable even at low levels.
Lansat Berry

 

[CatExe]

Change it to activate at half HP
Gale Wings

 

[Pasio]

Bring back Gen 6 Gale Wings


Prankster

 

[Lone_Garurumon]

I'm not sure quite how viable this is to code, especially with edge-cases such as switching, but I feel like you should still be able to use status moves on Dark-Types, just without the priority. It feels a little weird that Dark-Types completely negate a Prankster's gameplan, rather than just taking away the bonus.

Illusion

 

[Camille]

Keep, it is a cool Ability.
Dark Pulse

 

[Ghost Diplocaulus]

Keep

Steel Wing

 

[Camille]

Raise the power to 75, and the accuracy to at least 95, as it is rather underwhelming now.
Liquid Ooze