We already play Firebrand Archer in EDH decks that buff damage, and some of those commanders are in Standard, like Ojer Axonil, Deepest Might / Temple of Power, Ob Nixilis, Captive Kingpin, Urabrask / The Great Work, Taii Wakeen, Perfect Shot, Judith, Carnage Connoisseur, and Imodane, the Pyrohammer
Pauper: One of my personal favorite formats, Pauper is essentially Legacy Lite
With this in mind, this new Secret Lair variant probably doesnt have too high of a ceiling
It can easily destroy low-mana creatures, as you'll likely be loading up the graveyard with a few spells at the start of the game
Great for TCGs like Grand Archive, MTG, Pokmon, Lorcana & Flesh and Blood
My Marath Problem I build a lot of decks but there's a reason I haven't built Marath yet