22 cards where the cards aren’t reprints and the mana cost is greater than or equal to {3}{W}{U}{B}

The Ur-Dragon (Commander 2017 #48)
Atraxa, Grand Unifier (Phyrexia: All Will Be One #196)
Tivit, Seller of Secrets (New Capenna Commander #10)
Urza, Chief Artificer (The Brothers' War Commander #2)
Sharuum the Hegemon (Shards of Alara #194)
Conflux (Conflux #102)
Oloro, Ageless Ascetic (Commander 2013 #203)
Elenda and Azor (March of the Machine Commander #6)
Magister Sphinx (Conflux #116)
Primeval Spawn (Dominaria United Commander #13)
Enigma Sphinx (Alara Reborn #106)
Saruman of Many Colors (The Lord of the Rings: Tales of Middle-earth #223)
Nevinyrral, Urborg Tyrant (Commander Legends #287)
Sphinx of the Steel Wind (Alara Reborn #110)
Chromium, the Mutable (Core Set 2019 #214)
Meeting of the Five (Streets of New Capenna #202)
Shattered Seraph (Streets of New Capenna #221)
Dromar, the Banisher (Invasion #244)
Sphinx Sovereign (Shards of Alara #196)
A-Shattered Seraph (Streets of New Capenna #A-221)
Coalition Victory (Invasion #241)
Who // What // When // Where // Why (Unhinged #120)

This search is finished. Now the real work can begin.