41 cards where the illustration contains “monarch”

Anax and Cymede (Duel Decks: Heroes vs. Monsters #11)
Brago, King Eternal (Conspiracy #41)
Brago's Favor (Conspiracy #3)
Brimaz, King of Oreskos (Born of the Gods #5)
Chicken à la King (Unglued #17)
Clambassadors (Unglued #18)
Custodi Soulbinders (Conspiracy #17)
Dub (Dominaria #15)
Feast of Succession (Commander Legends #127)
Felidar Sovereign (Secret Lair Drop #1182)
Forced Fruition (Wilds of Eldraine: Enchanting Tales #18)
Goblin King (Seventh Edition #190)
Goblin King (Fifth Edition #236)
Goblin King (Limited Edition Alpha #154)
Goblin King (Secret Lair Drop #19)
Happily Ever After (Throne of Eldraine #16)
Kenrith, the Returned King (Throne of Eldraine #303)
King Macar, the Gold-Cursed (Journey into Nyx #74)
King Suleiman (Arabian Nights #6)
Lady Sun (Portal Three Kingdoms #45)
Linden, the Steadfast Queen (Throne of Eldraine #20)
Mercurial Pretender (Magic 2015 #68)
Mercurial Pretender (Magic 2015 Promos #68)
Murder (Magic 2013 #101)
Nekusar, the Mindrazer (Commander 2013 #201)
Oona, Queen of the Fae (Shadowmoor #172)
Oona, Queen of the Fae (Secret Lair Drop #54)
Overgrown Tomb (Secret Lair Drop #130)
Pixie Queen (Legends #196)
Putrefy (Strixhaven Mystical Archive #63)
Queen Marchesa (Conspiracy: Take the Crown #78)
Regicide (Conspiracy: Take the Crown #45)
Rulik Mons, Warren Chief (Dominaria United #316)
Savra, Queen of the Golgari (Ravnica: City of Guilds #225)
Sedris, the Traitor King (Shards of Alara #193)
Sol Ring (Tales of Middle-earth Commander #410)
The Akroan War (Theros Beyond Death #124)
Unexpected Potential (Conspiracy #12)
Vampire Sovereign (Core Set 2019 #125)
Vraska, Golgari Queen (Guilds of Ravnica #213)
Vraska, Regal Gorgon (Guilds of Ravnica #269)

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