First, I'd like to say, Dark Candy Fiddlesticks is the first Christmas Skin I genuinely like. Mainly I like it for how different it is, the sinister Nightmare before Christmas/The Grinch feel to it is just awesome.
However, after seeing the finished particles, I have to say I'm very disappointed, and if they're that boring in the final product, I likely wont buy it.
But, I'm giving Riot a fair chance to restore my faith in Christmas Skins, so here is my feedback.

General: First I want to talk about his particles in general. All the frozen particles seem very unimpressive and lackluster when compared to other frozen/ice themed skins. Whilst snow is just plain white in reality, the boring plain white colour for particles doesn't do much for the skin. Some of the particles is barely visible and just boring in general. I just simply think it needs a little more. Look at Frost Queen Janna, whilst her abilities is frozen they got that nice blue frost tint. DC Fiddle could benefit from something similar.
I also think some frozen glitter/sparkle effects would help, similar to those seen on Snow Day Ziggs snowballs. You know, those small star looking things. Just these two small changes would define his abilities a lot more!

Model: I'm happy with the model overall. Some people dislike the dark colours in-game compared to the lighter colours in the splash art. I actually think the darker purple fits him, he is after all DARK Candy Fiddlesticks. However, one thing I do think could be improved is his face. Make it more sharp/edgy/defined like it is in the art.

Recall: *Yawn* It was a struggle to actually see the particles, barely visible at all. Give his recall a more aggressive(but small) snowstorm. Also include what I said in the general section.

Auto-attacks: Cool particle, but again, could benefit from what I said in the general section. Also noticed quite a lot people actually liked the dark particles for his AA, so I thought up a cool idea which would be truly unique for a skin. What if his AA altered between two colours, to add to the candy cane feel? Imagine if it would alter between a frozen white/blue AA, and every other AA would be dark purple energy. That would certainly be unique and something new for a skin. If that is too much to ask, stick with my first suggestion, define the frozen feel more.

Q: Not much to say here, after all his fear was never very effect heavy. The ghosts/spirits look good. I do have a little idea, though. Give the little fear smiley a smug Grinch smile( http://momoftwoandahalfboys.files.wo..._by_rikona.jpg ), similar to how Surprise Party Fiddle have a hat on his fear smiley.

W: This one is just odd... I get you wanted a frozen feel to the skin, but sucking frost out of people is just silly, and doesn't really work out. Something I think I could be really cool here, would be a barber pole effect. Basically, it would look like a candy cane swirling slowly around. This would obvious share the white and dark purple of Fiddle himself. Alternatively, use those swirly spirits during fear cast, and make him suck those out of people.

E: This one is pretty much perfect. It actually got a blue tint already, good job! If anything, maybe add the glitter/sparkle effect, but otherwise you nailed it.(Edit: It actually does sparkle/glitter on the last hit, but would be nice if it did so in flight too!)

R: The effect when you initially cast it, just need the changes I have in the general section. The effects when CROWSTORM is actually cast, needs work. It needs to look more aggressive, throw more frost particles in there to make it look more brutal. Some more defined frozen whirlwind effects(Those "lines" you generally see in a whirlwind, look on Frost Queen Janna) would work wonders!
But more importantly, add the CROW back to CROWSTORM! You made a great new crow particle for his E, so why not use it in his ult? Throw a bunch of crows in there(E particle), and add the Crow noises again, whilst keeping the cool snowstorm sounds.
On a different note about his R: His walk animation during it is brilliant, great job!

When looking on the Skin Spotlight for the skin, I see way too many people say they favoured his placeholder particles. That is a very bad sign Riot. Most people say it's because they favoured the dark feel before, and at first I thought I disliked the new particles for the same reason. However, ultimately I think the reason why people favoured the placeholders over the new particles, is because the new particles feels unpolished and undefined, and are hardly noticeable in compare to the placeholders.

Please hear me out on this feedback Riot, this might be the only Christmas skin I will desire, ever! For all I care make it 1820 RP, but for the love of Christmas, put more effort into it!

Feedback from a Red would be appreciated.

Simply don't understand why a candy scarecrow wields ice magic. It's like two different themes splattered together. Maybe Dark Wind should throw candy crows, Drain could be a line of caramel and Crowstorm have some candy crows flying around; so as to better mesh the two concepts together.

Changing Fiddlesticks limbs from candy to ice would be another better option but it might imply more work and also remove the candy theme entirely from the skin; which may not be such a good idea.

The point is that he's a candy being using ice: the concepts aren't related at all. Something that meshes both together would help with the visual consistency.

His weapon is made of ice, though. So to some extend it DOES make sense for him to use frozen magic. In my opinion they just need to define his frozen magic way more, it's currently some of the most boring frost particles I've seen in-game. They just ooze of "boring".

However, I would personally favour dark energy myself. But, I think it's unlikely to expect them to rework all his particles completely, so it's more realistic to ask them to improve what they got already.

I think one thing that would really spruce this skin up a bit would be to have stronger howling wind effects. I didn't even notice the sounds on his recall animation because the recall was significantly louder.

W: Should have a "scary" windy effect like this: https://www.youtube.com/watch?v=b9NlVu2UEu0
R: Should have a blizzardy sound effect like this: https://www.youtube.com/watch?v=GQAiB9Vlbh0

Add something like that in and this skin would instantly become 3x cooler.

The new Fid skin Dark Candy:His spells effect is way too plain, we can barely see the spell effects, they look like that fid is not even using his spell while fid is actually using his spell. I love Fid, he is my fovrite champ I would totally love to my his skins, but this skin's spell effects have no features.
imo, even those incompleted spells effects with some dark fog were better than these completed spells effects.
I am so sorry to say that I am really disappointed at this new fid skin.
I hope you guys will make those spells effects more superb/gorgeous.

P.S. the champ mod is really good. the only problem is the spell effects

Dar Candy Fiddlesticks should suck souls from his target, like the ones that surround him when he fears people.

I don't know if this is just when I use the candy skin or always(I've only used the Dark Candy fiddle in PBE), but when fiddle is done with his Drain, he just stands there, instead of auto-attacking the remaining creeps or enemies. Is this normal or a bug?

I'm not sure if this is a skin bug, or just a general one, but I started a game as Fiddlesticks with the new skin, and was receiving no bonuses from masteries or runes. I don't know exactly what this is, but it was rather irritating.