Mystic Tomato If youve played any sort of old-school Yu-Gi-Oh, then youve definitely played Mystic Tomato
Applejack Honestly, Applejack feels like a Limited bomb
$54.99 Teferi, Hero of Dominaria Masterpiece Series: Mythic Edition $0.79 Bone Shards (Retro Frame) Modern Horizons 2 Variants $9.49 Gideon of the Trials (SDCC 2017 Promo Foil) Promotional $2.99 Talisman of Curiosity (Foil Retro Frame) Modern Horizons - Retro Frames $22.99 Fanatical Devotion Nemesis $6.99 Ashiok, Nightmare Muse (Borderless) Theros Beyond Death Variants $84.99 Chandra, Torch of Defiance (SDCC 2018 Promo Foil) Promotional $12.99 Impulsive Maneuvers Odyssey $27.99 Oko, Thief of Crowns (Borderless) Throne of Eldraine Variants $4.49 Priest of Forgotten Gods Ravnica Allegiance $24.99 Viscera Seer (Extended Art) Commander Legends Variants $15.99 Smokestack Urza's Saga 0 results found

Note that, because thats playing the full twenty fetchlands, unless you want Evolving Wilds, your mana gets worse after that, so its hard to justify even considering going over 80 cards in Standard, but I can imagine a reasonable case for anywhere between 60 and 80 moving forward, especially thanks to Ben Rubins proof of concept
And it is typically based on changes in the game's balance or mechanics