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

Bedevil (Ravnica Allegiance #157)
Ruinous Ultimatum (Ikoria: Lair of Behemoths #204)
Blood for the Blood God! (Warhammer 40,000 Commander #108)
Rakdos, Lord of Riots (Return to Ravnica #187)
Bladewing the Risen (Scourge #136)
Nicol Bolas, Dragon-God (War of the Spark #207)
Cruel Ultimatum (Shards of Alara #164)
The Balrog of Moria (Tales of Middle-earth Commander #46)
Nicol Bolas, Planeswalker (Conflux #120)
Progenitus (Conflux #121)
Rakdos, the Muscle (Outlaws of Thunder Junction #226)
Piru, the Volatile (Modern Horizons 2 #207)
Rankle and Torbran (March of the Machine #252)
Nicol Bolas (Legends #246)
Akul the Unrepentant (Outlaws of Thunder Junction #189)
Prince of Thralls (Shards of Alara #182)
Malfegor (Conflux #117)
Rakdos the Defiler (Dissension #129)
Unscythe, Killer of Kings (Alara Reborn #114)
Violent Ultimatum (Shards of Alara #206)
Defiler of Souls (Alara Reborn #37)
Rakdos Firewheeler (Ravnica Allegiance #197)
Vaevictis Asmadi (Legends #269)
Gwendlyn Di Corci (Legends #228)
Rohgahh of Kher Keep (Legends #255)
Rakdos Augermage (Dissension #127)
Tor Wauki (Legends #265)
Axelrod Gunnarson (Legends #219)

The arc of my blade has carved a path of light to the end of these results.