46 cards where the cards aren’t reprints and the mana cost is greater than or equal to {W}{U}{B}{R}

Esika, God of the Tree // The Prismatic Bridge (Kaldheim #168)
Esika, God of the Tree // The Prismatic Bridge (Kaldheim #168)
The Ur-Dragon (Commander 2017 #48)
Jodah, the Unifier (Dominaria United #203)
Tiamat (Adventures in the Forgotten Realms #235)
Maelstrom Nexus (Alara Reborn #130)
Sliver Hivelord (Magic 2015 #211)
The First Sliver (Modern Horizons #200)
Two-Headed Hellkite (Dominaria United Commander #14)
The Kami War // O-Kagachi Made Manifest (Kamigawa: Neon Dynasty #227)
The Kami War // O-Kagachi Made Manifest (Kamigawa: Neon Dynasty #227)
Sliver Legion (Future Sight #158)
Sanctum of All (Core Set 2021 #225)
Scion of the Ur-Dragon (Time Spiral #246)
Maelstrom Archangel (Conflux #115)
Sliver Overlord (Scourge #139)
Breya, Etherium Shaper (Commander 2016 #29)
Conflux (Conflux #102)
O-Kagachi, Vengeful Kami (Commander 2017 #45)
Unite the Coalition (Dominaria United Commander #15)
Progenitus (Conflux #121)
Garth One-Eye (Modern Horizons 2 #197)
Niv-Mizzet Reborn (War of the Spark #208)
Tom Bombadil (The Lord of the Rings: Tales of Middle-earth #234)
Sliver Queen (Stronghold #129)
Jared Carthalion (Dominaria United Commander #2)
Chromanticore (Born of the Gods #144)
Sliver Gravemother (Commander Masters #707)
Primeval Spawn (Dominaria United Commander #13)
Iridian Maelstrom (Dominaria United Commander #12)
Child of Alara (Conflux #101)
Invasion of Alara // Awaken the Maelstrom (March of the Machine #230)
Invasion of Alara // Awaken the Maelstrom (March of the Machine #230)
Horde of Notions (Lorwyn #249)
Rukarumel, Biologist (Commander Masters #711)
Fusion Elemental (Conflux #107)
Niv-Mizzet, Supreme (March of the Machine: The Aftermath #40)
Karona, False God (Scourge #138)
Cromat (Apocalypse #94)
Niv-Mizzet, Guildpact (Murders at Karlov Manor #220)
Yore-Tiller Nephilim (Guildpact #140)
Genju of the Realm (Betrayers of Kamigawa #151)
Meeting of the Five (Streets of New Capenna #202)
Last Stand (Apocalypse #107)
Atogatog (Odyssey #286)
Begin the Invasion (March of the Machine Commander #79)
Coalition Victory (Invasion #241)
Urza, Academy Headmaster (Unstable #136)
Who // What // When // Where // Why (Unhinged #120)

Though this query has ended, its relics still slumber in New Argive.