I'm back on my Modern BS. I've got Izzet Phoenix sleeved up and ready to go. I initially bought into it because it was a good deck that looked fun to play, but now within the past few weeks, annoyingly, it's become the consensus "Best Deck". Annoying because now it's just gonna look like I'm the guy that plays whatever the best deck is. I just wanted to have some semi-janky fun, I'm sorry, I didn't know things were gonna be like this! But I did pay $25/ea for these Phoenixes, so you bet your ass I'm gonna play them.
The agreed upon core deck atm seems to be:
4x Arclight Phoenix
4x Thing in the Ice
2x Crackling Drake
4x Opt
4x Serum Visions
4x Thought Scour
4x Faithless Looting
4x Lightning Bolt
4x Manamorphose
2x Gut Shot
18x Lands
Which gives you 6 flex slots. Everyone runs 2 more creatures, but the split is whether to run 2x Pteramanders or 2x Snapcasters. Snapcasters give you more flexibility, but Pteramander gives you a 5/5 flying beat stick, so that's got some obvious appeal too. Some people run 3x or even the full 4x Gut Shots, I think I'm gonna keep it at 2x. Surgical Extractions in the mainboard are a thing now, either 1x or 2x, I'm thinking of going 2x, to have 4 "free" spells in total. Then in the final slots, people tend to play some extra removal, generally a mixture of 0-2 Lightning Axe, Izzet Charm, and Beacon Bolt. Lightning Axe is powerful removal that synergizes with your plan of getting a phoenix in your graveyard. Beacon Bolt is a 2-for-1 removal that also helps get a card in your card, but at a lot higher cost. Izzet Charm can kill a weenie, be Faithless Looting #5, or counter something annoying.
For now, my final six slots are:
2x Pteramander
2x Surgical Extraction
1x Lightning Axe
1x Izzet Charm
The SB is still undecided. I'd like to have a 3rd Surgical Extraction in the board, but I only own 2 so I've either gotta try to find another (and they're ~$50

) or sub in a Ravenous Trap (which is what I'm leaning toward right now). Ravenous Trap seems better against Dredge anyway. Some amount of Abrade and/or Shatterstorm seem like a must. I'd like to have access to a few Young Peezys for when it looks like I might get cut off from my graveyard. A few extra Lightning Axes, maybe a Sweltering Sun or two for creature heavy decks. (Anger of the Gods is kind of a no-go, since you don't want accidentally exile your own Phoenixes). Blood Moon is good against Tron, but I've also heard of people running Molten Rain + Surgical Extraction to hit Tron lands, which also seems pretty dope. Burn is a terrible match-up, so you want 2+ Dragon Claws to try to survive.
Sideboarding for Modern is basically impossible, you just pick a few of your worst or most likely matchups, and hope for the best.