Trying The Key to the Vault as a creature cheater enabler.
You sort of have to curve out with turn 1 evasive creature like Spyglass Siren, play Key on turn 2, then turn 3 try to get an attack through and hope you hit a big payoff off the top. Doesn't seem reliable but maybe it can work a little.
Other key-carrier creatures I'm trying are Harrier Strix to help clear out blockers and Elusive Otter to help pump up attackers. The Otter is mainly why I'm pushing a bit into green. I'm hoping Ingenious Prodigy can work as either a key-carrier with the Skulk or as a bit of library digging.
I'm also putting in Bramble Familiar to give some ramp if I have an awkward start. But it's decent as a payoff card since you can payoff into the Fetch Quest side to get a better chance to hit a top end payoff.
Payoff cards include the classic Atraxa, Grand Unifier and Etali, Primal Conqueror
and Portal to Phyrexia. Other strong payoffs are Nissa, Ascended Animist (though we don't have many Forests), Vein Ripper and Titan of Industry.
I'm also putting in some personal favorite payoff cards in Olivia, Crimson Bride to reanimate other power cards, The World Spell to clear out some big cards getting bottlenecked in hand, Lord Xander, the Collector to be a pest on the opponent's resources, and Ziatora, the Incinerator is a sneaky oppression with the reanimation tools and the treasures it makes just unlock anything else stuck in hand.
I'm testing out Nexus of Becoming as an indirect payoff card. Seems like it's another way to cheat out half of my big creatures or a Portal. And at 6 mana it's maybe hard-castable if I flood out a bit and get a couple Familiars in play without a Key. Nexus can also cheat a Key into play.
With the Nexus I feel like I can try a couple Equipment to support the Siren in combat. Lost Jitte maybe could be a real thing? Glowcap Lantern has always been trash but maybe exploring onto a Prodigy can help with more digging and bigger power attacks make the Key payoff better, so I'm giving it a try. Nexus can turn either into a 3/3 at least.
For lands I want a low land count (but I do need reliable 3 mana by turn 3) with minimal ETB tapped states but support for green and some sort of filtering for all colors. I'm putting in the new Simic fast land Botanical Sanctum, and 9 Caves including some Forgotten Monument that can turn all the Caves into any-color pain lands with no ETB tapped effects. Doesn't leave much room for basics.
