24 cards where the card types include “legendary creature” and the colors is BRW and the mana cost is greater than or equal to {R}{W}{B}

Altaïr Ibn-La'Ahad (Assassin's Creed #45)
Caesar, Legion's Emperor (Fallout #1)
Edgar Markov (Commander 2017 #36)
Ghen, Arcanum Weaver (Commander Legends #275)
Isshin, Two Heavens as One (Kamigawa: Neon Dynasty #224)
Jan Jansen, Chaos Crafter (Commander Legends: Battle for Baldur's Gate #277)
Jirina Kudro (Commander 2020 #8)
Kaalia of the Vast (Double Masters 2022 #235)
Kaalia, Zenith Seeker (Core Set 2020 #210)
Kelsien, the Plague (Commander 2020 #11)
Kroxa and Kunoros (March of the Machine #245)
Licia, Sanguine Tribune (Commander 2017 #40)
Malik, Grim Manipulator (Universes Within #23)
Mathas, Fiend Seeker (Double Masters 2022 #252)
Olivia, Opulent Outlaw (Outlaws of Thunder Junction Commander #2)
Oros, the Avenger (Commander Anthology #188)
Piru, the Volatile (Modern Horizons 2 #207)
Queen Marchesa (Outlaws of Thunder Junction Commander #239)
Shanid, Sleepers' Scourge (Dominaria United Commander #4)
Snapdax, Apex of the Hunt (Ikoria: Lair of Behemoths #209)
Syr Gwyn, Hero of Ashvale (Throne of Eldraine #330)
Tariel, Reckoner of Souls (Double Masters 2022 #281)
Vihaan, Goldwaker (Outlaws of Thunder Junction Commander #8)
Zurgo Helmsmasher (Khans of Tarkir #214)

Their mind whirled with grand plans, never thinking of what might happen if they got to the end of the list.