So, initially I biult this deck as Izzet Prowess from precon Arcane Tempo, and with further upgrades it became UR Blitz (my pocket are crying from this prices...). I'll make another deck for Pioneer, based on precon, and it will be Izzet Phoenix, but this one is going to be different, and here's why - it's too slow versus decks i've played, and now I see reasons why meta UR blitz is like that. It's really not much to describe, take any meta desklist, and you'll have mine. I'll move all section below in future phoenix deck for pioneer, as it fits more for pioneer, but for now it will be here, 'cause i'm lazy mf (and i don't have all cards to build around).

But advise remains the same: don't buy Arcane Tempo, Arclight Phoenix and Big Daddy is not worth it, buy singles. But If you're as "smart" as me to buy it and you thought "Well, WotC made the product for playing right out of the box in my local store/club to win some events, yay", make yourself at home, we're gonna tech and cut off a lot, 'cause it's not playable.

We got some good cards to build around, but here's the problem: they're totally from different types of deck, so they won't synergize well.

You've got Arclight Phoenix, which is a great card, but he's ALONE, and you need all 4 of them to be good, and you have to cut a lot of cards, like Niv-Mizzet and Murmuring Mystic, 'cause they're too slow for such deck, not mentioning that you need to discard your hot boys, and Chart a Course, even we're having 4, not really helps (Thrill of Possibility will help, though). Phoenix is a great deck type, still popular, still fun to play, take 3 more Phoenixes, cut off slow creatures, add spells to support your birdies (you have a lot of choise), gg wp, definetely go for it.

Drakes. We have Crackling Drake, we have some cheap cantrips, most viable upgrade in terms of budget. Take out Niv-Miz, take out Phoenix, not really need them. For drakes you can take Enigma Drake as well, a little bit worse than Crackling Drake in terms of scaling (doesn't scale with exiled cards, graveyard wipes can hurt you) and they won't draw you a card, but they're cheaper in mana, really solid snake. Deck battleplan is straightforward: put your flyers, cast your cantrips, scale them, protect them with Dive Down or/and put some counterspells, like Lofty Denial (you are Blue or what?), kill opponent. Good deck type for it's price, so if you're on budget - go for it.

And, we left with Niv-Mizzet, Parun. The most obvious answer would be like "Put a Storm on it", but here's the thing: his mana cost. It's 6 mana, 6 colored mana, he's really mana intensive, and most Storm decks build around spells (who could even guess...) and someone/something who will help to cast it twice, copy it, return it to hand or help to cast it cheaper, like Goblin Electromancer we have in the deck. I mean, i like Daddy, Daddy is cool, he's a real threat on board if he's not answered fast, but first, he will be answered pretty often, and second - in Storm deck you have better spells to cast for 6+ mana to win you game. But no one will stop you from build a deck around him, i would like to look at deck like this, pm me if you have it. But for now, one of my Big Brain Dragon goes to EDH to wheel some shit out of people...

So, we know main ways for upgrade, and now question is what to put in:

Stormwing Entity and Sprite Dragon. For 3UU, Stormwings is just mmm, fine creature, but you never gonna hard-cast them, because you have plenty of cheap spells like Opt, Shock, you name it. For just 1U you're scrying for 2, having FLYING prowess, and this is really powerful creature, definetely take them. Sprite Dragons is like stacking Prowess, but for entire game, this is ridiculously powerful flyer. They have haste, so be careful with traps, like turn 1 attack vs. flash-creature decks, build them up in your cheap-spells gym, and go. Absolutely bonkers.

The Royal Scions is the only planeswalker(s?) that fits for me - for 1UR you get 5 loyalty planes', who can filter your topdeck or gives nice buffs for your creature, which in most will be unblocked because of first strike. And his ultimate in worst cases is 4 damage and you've got 4 cards, which is great. Perfect for this deck. Most of the time, opponents will try to take it down, so if Scions are heavily focused, use this time to build up your Sprite Dragons.

Card draw. Chart a Course is fine, but it has condition, which is not great. It's fine for Phoenix, but if you're going Drakes or maybe Prowess, consider Winged Words or Frantic Inventory. Winged Words are more stable, with less bearable condition, but i personally took Frantic, 1 card for 2 mana is not cool, but 2 and more is awesome. Radical Idea has been cut, i can see jump-start draw in Phoenix, it fits well, but it feels clunky for me in Drakes or Prowess.

Upgrades:

Mana base. Most important upgrade. By deafult, you have 2 Sulfur Falls, make it 4 ASAP rocky, try to take out Izzet Guldgate for Steam Vents, it's pricey, but very spicy, will fix your mana. I personally fine with 22 lands, but you can go with 20-21 to make room for spells, it's up to you, don't be afraid to experiment.

I've got 4 Brazen Borrower. I robbed a bank for it, bit they were worth it. It's 1U bounce, and we have Vapor Snag, but it targets any nonland, so it's fine for me. Can't quite remeber i've ever played creature side, your other threats are much faster and better.

Bonecrusher Giant is actually good card if you gonna be more burn-like, 2 unblockable damage, 4/3 body with good passive, use it if you want more creatures.

Raking Claws. Nice instant, double strike, which can accidently win you games.

Feel free to comment. Peace, mages.

P.S. I've rapidly swaped for Blitz as soon as i played versus tier 1 decks of format. Main emenies in my area are Amulet Titans and UW Spirits, and if I still didn't play vs. spirits, i did versus amulet, and they annihilated me 2-0 in 3 turns. I had chances to win (maybe), but I really felt like i can't catch versus that.