Demilich looks like one of the strongest cards from Adventures in the Forgotten Realms, if not the best. Any time there’s a card that can be cast for free, it’s good to take notice because those cards often end up being broken. Historic Izzet Phoenix looks like a very natural fit for Demilich because you’re both playing a lot of instants and sorceries and playing a lot of them in one turn.
4 Arclight Phoenix 4 Brainstorm 4 Demilich 4 Expressive Iteration 2 Fabled Passage 4 Faithless Looting 2 Finale of Promise 1 Fry 2 Island 1 Lightning Axe 2 Magma Spray 2 Mountain 4 Opt 3 Pillar of Flame 4 Riverglide Pathway 4 Spirebluff Canal 4 Sprite Dragon 4 Steam Vents 1 Stormwing Entity 1 Crackling Drake 3 Sulfur Falls Sideboard 2 Brazen Borrower 2 Soul-Guide Lantern 1 Mystical Dispute 1 Ox of Agonas 2 Anger of the Gods 2 Lava Coil 2 Negate 1 Improbable Alliance 2 Fry
It also works really well with Faithless Looting, as you can just ditch it in the early game and then cast it from your graveyard for free later when you are casting multiple cards a turn. You don’t even need to focus on casting four spells to make it free. A Brainstorm and a Faithless Looting to make it cost two mana is a perfectly reasonable deal.
There aren’t very many cards you can replace with creatures in Phoenix other than some of the creatures themselves because you need to keep the spell count high. Replacing Ox of Agonas, Stormwing Entity and Crackling Drake with them makes the most sense to me.
If it was only a 4/3 which would let you cast it from the graveyard, it would still be pretty strong, especially in grindy matchups, but what really pushes it over the top is the ability to “flashback” spells for free from your graveyard when it attacks.
Don’t sleep on Demilich and try to abuse it in as many decks and as many ways as possible. It has a very high chance of being the most broken card of the entire set!