So.. I´m quite far from having the WC to build this deck but I guess we can start at least discussing its chances of becoming a real thing, this is my first attempt in a Grixis Shell

Creature(3):
3 Niv-Mizzet, Parun

Instant(27):

4 Syncopate
2 Blink of an Eye
2 Essence Scatter
4 Lightning Strike
4 Risk Factor
4 Ionize
4 Chemister's Insight
3 Discovery // Dispersal

Enchantment
2 Eldest Reborn


Planeswalker(3):
3 Ral, Izzet Viceroy

Lands(25):
6 Island
4 Mountain
4 Steam Vents
3 Drowned Catacomb
4 Sulfur Falls
4 Watery Grave

Discovery seems like a solid card especially with all the Jump Start cards of the deck, and Eldest Reborn could be huge bringing back Niv with open mana.

I´m sure a lot of us is thinking about this deck so let's get busy

So far Risk Factor has been the absolute worst card in the set. Never pans out the way you want it to unless you are already winning. I have played 3 games I remember where my opponent played Risk Factor and I won them all easily.

I'd take that out and replace it with either more counters or some Vraska's Contempt.

Also, up the land count by 1. This type of deck lives and dies by the ability to cast its spells, sometimes multiples. If you draw too many you have Chemister's Insight to toss them to in the mid to late game.

Edit: Worst hyped-by-some card...Book Devourer has the worst card locked in for the most part.

Yup I can see the point I really havent played the card yet so I´m just guessing, and I totally forgot about search for azcanta... and it definitively has a place here I dunno if black is worth the splash... maybe I Jeskai with Teferi should be better.... hmm

Izzet Primal Amulet is almost certainly a much better shell.

Risk factor has been pretty good in my mono-red singleton deck. It's very similar to the red gearhulks in effect. You only cast it early if you want to start chipping away at their life-total and late game it's a draw spell. It's no use thinking it'll work any other way.

I think you need the only red sweeper available to survive all the go wide decks (fiery cannonade). Don't think you can 1-for-1 them for long.

Also, I'd be tempted to play the Electrostatic Field, just to block and ping.
I'd definitely play Jaya too.
I'm thinking mirari conjecture/primal amulet is the way to go too.
Izzet is probably were I going when I get sick of aggro.

Risk factor would be good in the sideboard for some mid-game draw/burn especially against control, but unless you are ahead giving your opponent the choice in the matter with a card that does not affect the board is a bad card. Maybe as a two-of MD, but it would be the first thing I cut.

Agree with needing sweepers. Clarion call would be my first choice and shouldn't be too hard to splash. Plus it would open up Teferi and Ral for your Planeswalker pals.

I mean, if you're going to go control, go full control and wreck face. No half-measures.

Risk Factor was out of place here, I built another pile but its very far from being completed too much WC on lands, I think the Electrostatic Fields might be the way to go to chip in damage while you build a big turn to end things,Goblin Electromancer might have place here to enable those big turns where you cast a bunch of spells pinging your opponent.
Anyone thinks Beacon bolt is standard material?... maybe a one of?... that thing can deal with almost everything in the late game.

Ok Counter Burn 2.0
I ditched black coz it was not worth it and I built a pure Izzet approach, I have been testing a diluted version of it -without all the dual lands and just 2 Niv Mizzets, 2 Ionize and just one Ral...
Chemister´s Insight has been huge, I think 3 copies is just about the right number 4 may be too much, and is great dropping them to the GY with Ral... the card advantage this thing provides is just overwhelming it might be a win con on its own.
Electromancer and Electrostatic Field have been great too, they make the Counter Burn plan work and once Niv lands things just get out of hand in a rush in one of those BIG turns where you cast 5 spells deal 10 damage and draw 5 cards... So much FUN!
Anticipate has overperformed as well as Syncopate protecting us in the early stage of the game, and providing consistency and flexibility.

I haven't been able to double cast a Spell with Expansion but I have been able to win a counterspell fight with it... I dunno if Missions Brefing might have a place here... Still waiting for them to show up in the ICR -fingers crossed-
Same with Search for Azcanta... that thing could Flip T5 consistently... and I think I will test one copy of Beacon bolt and see how it works.

Creature(11):
4 Electrostatic Field
4 Goblin Electromancer
3 Niv-Mizzet, Parun

Instant(23):
3 Syncopate
4 Anticipate
1 Essence Scatter
1 Blink of an Eye
2 Sinister Sabotage
3 Fiery Cannonade
4 Ionize
3 Chemister's Insight
2 Expansion // Explosion

Planeswalker(2):
2 Ral, Izzet Viceroy

Lands(24):
9 Island
9 Mountain
4 Steam Vents
4 Sulfur Falls

The fields suck! they are just cute... and as Windervoid said Expansion//Explosion is bugged... you can´t double cast your own spells...
I did use one WC on Search for Azcanta -coz it goes in so many decks- and its obviously great...
Syncopate is overperforming... and Ral is kinda meh on T5
I wish we had a better sweeper on red... Star extinction is a bit over the top but I guess it should fill the panic button slot...

I did get Exansion to work last time I tried it. CTRL and a stop on the phase let me double cast Clarion. I am positive I have tried that before and it did not work, but since I was able to get it to work, I will go with human error on my part....or maybe it depends if your opponent has a potential reaction if it was not my human error?

Anyway, I was at 70%+ on my Jeskai build like this, and it has just tanked recently. Not sure if I just had a good streak before and bad streak now, but I am guessing it has more to do with a maturing meta. Decks are more sweeper resistant and seem a bit faster then they were a week ago.

I haven't tried adding a stop on the phase... but I did try the full control thing and the spell resolve as soon as I pay for it without giving me a chance to cast Expansion... I will try your method and see how it works... casting 2 times Fiery Canonade should have saved my ass more than once.

here is my pile ATM, its becoming Izzet control more than counter Burn... I think that the pile I originally think should use Guttersnipe, Steam Kin, Electrostatic Field, Risk Factor + Counters.... anyway... here is my current build

Creature(9):
4 Goblin Electromancer
2 Rekindling Phoenix
3 Niv-Mizzet, Parun

Instant(20):
4 Syncopate
4 Anticipate
1 Blink of an Eye
3 Fiery Cannonade
4 Ionize
3 Chemister's Insight
1 Expansion // Explosion

Sorcery(3):
3 Lava Coil

Enchantment(2):
2 Search for Azcanta

Planeswalker(1):
1 Ral, Izzet Viceroy

Lands(25):
10 Island
8 Mountain
4 Steam Vents
3 Sulfur Falls

I was so impressed by nox's deck that I blew 3 mythic WCs on Arclight Phoenix.
The idea is simple, lots of cheap spells, especially draw and burn and get the Phoenixes into the yard by discarding them to jumpstart. Then any time you can cast 3 spells pre combat, you get 1 or more free hasty Phoenixes to beat face.
It actually works, even with my gimped build that is missing most of the best cards.
I've had to improvise with some ral, niv and some rekindling Phoenixes to fill some holes.
I didn't actually see his whole list because I wanted to try it from scratch without being biased, but I've put a working albeit janky version together.

Sweet and off-beat deck. I take my hat off to nox for this one.

I have one or 2 of those... I think there is a deck Janky as hell but incredibly fun, but 3 MWCs!!! on them!! that's madness!!
I would love to take a look at that pile, I was hyped about that deck during spoiler season, I was thinking on:

Chart a course, Radical Idea and Electromancer as some enablers + Burn and bounce... for tempo...
- Hell... I went and made a draft... of what I was thinking-

Creature(8):
4 Goblin Electromancer
4 Arclight Phoenix

Instant(22):
2 Opt
4 Shock
4 Radical Idea
4 Blink of an Eye
4 Lightning Strike
4 Chemister's Insight

Sorcery(7):
4 Chart a Course
3 Lava Coil

Lands(23):
10 Island
5 Mountain
4 Steam Vents
4 Sulfur Falls

That's more or less the deck. Nox has a video on YouTube (that's were I saw the deck). Those mythic WCs were just sitting there anyway, not like I'm gonna craft teferi...

Nox was playing risk factor and some tormenting voice also.
In my jank version, I found hypothesizzle to actually be really good.
In your version, the spells are already so cheap that electromancer isn't doing much...
I found his list:
https://mtgarena.pro/decks/the-arclight/
He must have been experimenting with some stuff, because he played some cards not in the list on the videos.

This is the counter/burn I'm interested in trying first, not played it yet (and won't for quite some time). Went Jeskai, since Teferi is probably still the strongest card that's standard legal (and I got a free one with the promo and opened one in the singleton) and it gets access to a cheap sweeper which I think is vital.

4 Chemister's Insight (GRN) 32
4 Clifftop Retreat (DAR) 239
2 Crackling Drake (GRN) 163
3 Deafening Clarion (GRN) 165
4 Glacial Fortress (XLN) 255
4 Ionize (GRN) 179
3 Island (XLN) 264
3 Lava Coil (GRN) 108
3 Lightning Strike (XLN) 149
3 Mountain (XLN) 272
2 Niv-Mizzet, Parun (GRN) 192
2 Ral, Izzet Viceroy (GRN) 195
2 Risk Factor (GRN) 113
4 Sacred Foundry (GRN) 254
2 Search for Azcanta (XLN) 74
4 Shock (M19) 156
4 Steam Vents (GRN) 257
4 Sulfur Falls (DAR) 247
3 Teferi, Hero of Dominaria (DAR) 207

It's pretty all in on plainswalkers and Niv-Mizzet, but if you get to untap with the dragon the game should be over (Risk Factor is truly disgusting with Niv in play too - 6 mana deal 10/draw 2 or 6 mana draw 8/deal 8).

When I have the cards for it, I'll probably mess around much more with this deck. Especially cutting the burn for more efficient draw and go all-in.
Deck really needs a decent sweeper. Could go jaskai for Clarion, but that would make for some funky mana.
My main brain storm is adding drowned secrets to self-mill yourself and get those Arclights into the yard faster. Could also be a mill alternate win-con and open up sideboard options to go all out mill instead.

Turbo Arclight

4 Arclight Phoenix (GRN) 91
1 Banefire (M19) 130
2 Blink of an Eye (DAR) 46
2 Chart a Course (XLN) 48
2 Chemister's Insight (GRN) 32
2 Discovery // Dispersal (GRN) 223
2 Drowned Secrets (GRN) 39
1 Expansion // Explosion (GRN) 224
3 Ionize (GRN) 179
7 Island (GRN) 261
4 Lightning Strike (M19) 152
1 Mission Briefing (GRN) 44
7 Mountain (GRN) 263
4 Opt (DAR) 60
4 Radical Idea (GRN) 52
3 Risk Factor (GRN) 113
3 Shock (M19) 156
4 Steam Vents (GRN) 257
4 Sulfur Falls (DAR) 247

Everything is disgusting with Niv resolved.

Jeez, if this deck goes second, it wins about 20% of the time.

I have quite good results in B03 with it... Champion T2 on the draw is a nightmare scenario tho...

Fiery cannonade and lava coil have been quite good IME

This is my pile now... just got a 5-0 run on B03

3 Niv-Mizzet, Parun (GRN) 192
4 Syncopate (DAR) 67
4 Anticipate (M19) 44
2 Fiery Cannonade (XLN) 143
4 Ionize (GRN) 179
4 Steam Vents (GRN) 257
3 Sulfur Falls (DAR) 247
2 Ral, Izzet Viceroy (GRN) GR5
4 Goblin Electromancer (GRN) 174
3 Chemister's Insight (GRN) 32
2 Rekindling Phoenix (RIX) 111
2 Search for Azcanta (XLN) 74
1 Blink of an Eye (DAR) 46
2 Lava Coil (GRN) 108
8 Mountain (XLN) 275
10 Island (M19) 267
2 Lightning Strike (M19) 152

2 Essence Scatter (M19) 54
1 Disdainful Stroke (GRN) 37
4 Negate (RIX) 44
2 Lightning Strike (M19) 152
2 Lava Coil (GRN) 108
2 Banefire (M19) 130
2 Fiery Cannonade (XLN) 143

I´m amazed that Niv is not in the main deck in any of the Izzet piles on Goldfish... I find that guy insane