Of the three, Catacomb Sifter is easily the most powerful, so thats where I gravitated: Creatures (21) 4 Catacomb Sifter 4 Sylvan Advocate 3 Deathcap Cultivator 1 Tireless Tracker 1 Ishkanah, Grafwidow 4 Grim Flayer 3 Verdurous Gearhulk 1 Noxious Gearhulk Planeswalkers (6) Lands (24) Spells (9) This list is a bit slower than the G/W list, but in exchange it gets to take advantage of delirium
Two-for-ones really shine when your opponents are "playing fair" and they are giving you sufficient time to build your resources
Selvala, Heart of the WildsSelvala, Heart of the Wilds (Helms 4,692 Decks, Rank #230
Each Vehicle begins as simply an artifact
They also let me know they're actively working on implementing this system programmatically wherever possible
If the copied creature has in its mana cost, X is 0