First, that necklace looks pretty powerful
They are designed for Limited formats, give every player a fair card pool, and keep the opening experience exciting with foils, wildcard slots, and chances at extra rares
Grenzo, Havoc Raiser $3.99 If more people built aggressive decks in Commander, Grenzo might be one of the chase rares in Conspiracy: Take the Crown
What gives the edge to Offer over Swan Song for me is the ability to counter your own spell for two treasures
Right now, the top-selling Secret Lair card is the Rainbow Foil version of Encore Electromancer, a Hatsune Miku-flavored reprint of Snapcaster Mage that appears to have been distributed through a small, random percentage of Hatsune Miku Secret Lair drops
Harsh Mercy is fantastic here and should knock down any sort of large force your opponents may be accumulating so long as they arent playing tribal as well