Double Crisis focused on Team Aqua vs
Finale of Revelation requires 12+ mana to get all its perks, but that includes untapping some of your lands, shuffling your graveyard into your library, and removing your maximum hand size for the rest of the game
Finally, there is everyone else
Interestingly, that white/black hybrid mana symbol appears only in reminder text, so if extort appears on a black card, that symbol doesn't add white to its color identity for Commander deck-building purposes.) Fabricate Let's build stuff
Supporter card that allows both players to shuffle their hands into their decks and flip a coin to determine card draws
If you do start to buy booster packs and starter decks, you might also want to invest in a few deck boxes, some card sleeves, and something to hold your excess cards in when they arent in a deck