Phoenix lives again in historic! My favorite deck from RNA picks up several good cards from the historic card pool that give it additional life. Strategic Planning is our second best 2-mana cantrip and Lightning Axe gives us removal and another discard outlet. Phoenix shines against decks that can be easily disrupted by red removal or that are weak to your fliers. It is less good when the meta is full of decks that have a faster clock (burn/gruul aggro) or problem cards like Narset/Elder Garagroth. Curiously enough, the historic version of phoenix is resilient to graveyard hate more than people thing and it's a mistake to sideboard in Graftdigger's Cage against the deck. Only Finale of Promise is completely turned off by graveyard hate and people forget that you can cast phoenix normally.

Play Guide:

It's not possible to give a complete guide to phoenix. There are usually multiple lines of play every turn and chosen between them requires experience and knowledge of what you're playing against. Instead here's a quick summery of what I think are the most powerful things you can be doing on each turn.

T1: Kill their 1-drop, play a tapped land. Opt only if you are digging for a land or a creature.

T2: P kill their two drop, use Chart a Course or Strategic Planning to sculpt your hand for turn 3-4.

T3: Play a 1-mana spell and a Stormwing Entity. This is the first turn that you can bring back a phoenix and it's worth saving your 1-mana spells on turn 1-2 if you think you can get a turn like opt/crash through/lightning axe discarding a phoenix.

T4: Finale of Promise flashing back a removal spell and draw and bringing back 1-2 phoenixes. Final of Promise is your strongest spell as it always reaimates your phoenixes. It can easily be a 4-1 when you kill a creature, draw a card, and bring back 2 phoenixes.

Update: 3/10/21

With so much of the removal in historic targeted at low CC creatures (fatal push, eliminate, bloodchief's thirst, baffling end, claim the first born) we can get some equity by dropping all the lower costing creatures in our deck. This means cutting out the sprite dragons/young pyromancers. It's worse against decks lacking removal but better when we can dodge a number of their cards. The crackling drake/escape volicoty is also quite potent threat against decks that lack instant speed interaction.