Historic Izzet Delver and Phoenix are something between aggro and midrange with a little bit of combo elements as well. Dragon’s Rage Channeler and Sprite Dragon provide the aggression and Arclight Phoenix, with all the cheap spells and Faithless Looting, provides the combo element. Your plan is to curve out quickly, use removal to clear the way and set up for a turn where you cast three or more spells to bring back Phoenixes from the graveyard for free. This deck can kill quickly, but it can also grind out an opponent with a lot of removal by rebuying the Phoenixes over and over. Thanks to all the card selection, you always see a lot of cards every game and the deck is incredibly consistent.
Izzet Phoenix is solid against everything and doesn’t have very many weaknesses. In my opinion, it is a top three deck right now, right after Jeskai Control and Jund. It is also very flexible in terms of deckbuilding. If you’re trying to beat a heavy creature metagame, there are a lot of cheap removal spells you can play. On the other hand, if you’re trying to beat blue decks, it’s completely reasonable to put a couple of Mystical Disputes in your main deck. Thanks to Faithless Looting, you’ll never have any cards that would be completely dead in a matchup because you can always loot them away for something else.