The Monarchs are the rulers of the five civilizations.
As such, they are considered to be the largest and most powerful creatures in their (respective) civilizations.
Thousands of years ago, the five Creatures Monarchs were the rulers of the Five Civilizations. When a war between humans and Kaiju that threatened to destroy the entire world erupted, the Monarchs banded together with five human wizards to end the war.
The Creature Monarchs willingly sacrificed their mana energy so that the original Duel Masters might create the mystical Veil that has ever since separated the human and Kaiju worlds. Drained of almost all their energy, the five Monarchs fell into a deep slumber.
It appears the plan was originally to allow the Monarchs to recover their strength and awaken before sending them across the Veil so they might rule their civilizations again, but at some point, the Order of the Kaijudo Duel Masters betrayed the Monarchs' trust, periodically siphoning off their mana, keeping them in hibernation for millennia.
In The Rising Pt. 1, the Choten succeeds in his plot to awaken the Creature Monarchs and summons them to him.
In The Rising Pt. 2, the Creature Monarchs arrive where Almighty Colossus, Eternal Haven Angelic Liege, and Queen Kalima of the Infinite Dark starts to collapse the Veil. With help from Sasha, Channeler of Light, the Duel Masters used a Veil Creation spell to send the Creature Monarchs and the creatures that came at the time back to the Creature World.
In Clash of The Monarchs, the current Duel Masters persuade the four free Monarchs to call for a summit in the Null Zone in hopes of exposing the Choten's manipulation of Tritonus. A battle subsequently ensued in which the Choten's forces and the Duel Masters attempted to claim control of the Monarchs' artifacts and the Monarchs themselves. Due to the mana-draining properties of the Zone all five Monarchs fell comatose, though Master Kimora was confident that their mana production centers would prevent them from perishing like lesser creatures in the Zone.
List of Monarchs
Master Chavez | Gilaflame the Assaulter
Master Kimora | Mighty Shouter
Master Nadia | Aqua Chaser, Rusalka
Master Isao | Prism-Blade Enforcer
Master Jaha | Black Feather of Shadow Abyss
Original Duel Masters
Alcadeus, Winged Justice ● Argus, Vigilant Seer ● Beliqua the Ascender ● Blinder Beetle ● Citadel Magistrate ● Cobalt, the Storm Knight ● Cyborg Samurai ● Flare Inhibitor ● Halon ● Kolus, Soulshine Enforcer ● Lars, Virtuous Imager ● Luminar ● Nimbus Scout ● Orion, Radiant Fury ● Rain-Cloud Kraken ● Razorpine Tree ● Rodi Gale, Night Guardian ● Sentrus ● Shaw K'Naw ● Spyweb Scurrier ● Stalker Sphere ● Starlight Strategist ● Star Lantern ● Sun-Stalk Seed ● Urth, the Overlord
Aeropica ● Angler Cluster Hartl ● Aqua-Ranger Commander ● Aqua-Reflector Nomulos ● Aqua Rider ● Aqua Seneschal ● Aqua Surfer Fertil ● Aqua Trickster ● Bladefish ● Buoyant Blowfish ● Captain Orwellia ● Cyber Lord Corile ● Finbarr's Dreadnought ● Fluorogill Manta ● Hazard Crawler ● Hydro Initiate ● Hydro Spy ● Hydrobot Crab ● King Bullfang ● King Coral ● King Poseidon ● Knowledge Warden ● Man o' Warden ● Memory Swarm ● Midnight Crawler ● Mother Virus ● Rapids Lurker, Wwhhshrll ● Saucer-Head Shark ● Snapping Eel ● Steam Star Grapplog ● Vikorakas
Council of Logos
Finbarr ● Hokira ● Milporo
Arachnoir of Cobweb Cavern ● Armored Guard ● Dagger Doll ● Delisle-la of No Return ● Dream Pirate ● Drooling Worm ● Gaunt Boneweaver ● Ghost Spy ● Gigargon ● Gigabolver ● Gigastand ● Gigazanda ● Gorgeon, Shadow of Gluttony ● Grave Worm ● Gregoria's Fortress ● Gregoria, Princess of Malevolence ● Locomotivator of Bleak Trestle ● Marrow Ooze ● Motorcycle Man ● Mr. Smiles ● Mudman Fumes ● Necrodragon of Vile Ichor ● Phosphorescent Ghost ● Ravenous Web-Leg ● Scavenging Chimera ● Skeeter Swarmer ● Skeleton Soldier ● Skull Cutter ● Slyth ● Spinning Terror ● Swampstench Worm ● Trixo of Wicked Wood ● Trox, General of Destruction ● Tygrif ● Venom Worm ● Vicious Coffer ● Wandering Brain-Eater
Assault Dragon ● Badlands Lizard ● Blade-Rush Wyvern ● Blastforge Marauder ● Blastforge Slavetrader ● Blaze Belcher ● Bolgash Dragon ● Bolshack Dragon ● Branca the Treacherous ● Burnclaw the Relentless ● Chaotic Skyterror ● Draglide the Swiftest ● Drakon Weaponsmith ● Explosive Infantry ● Flametropus ● Galsaur Rock Beast ● General Charzon ● Hammer Dragon Foulbyrn ● Hissy ● Jetflame Lizard ● Kenina the Igniter ● Lava Leaper ● Magma Dragon Melgars ● Meteosaur ● Moorna the Vengeful ● Napalmeon the Conquering ● Om Nom Nom ● Onslaughter Triceps ● Rothos the Destroyer ● Skycrusher ● Skycrusher's Elite ● Skycrusher's Volcano-Ship ● Sledge Bot ● Snaptongue Lizard ● Volcanodon the Whipcracker ● Vorg
Ambush Scorpion ● Brave Giant ● Broadsword Butterfly ● Dawn Giant ● Earthstomp Giant ● Essence Elf ● Fear Fang ● Forest Hornet ● Gasbag ● Granite Avenger ● Hornblade Dragon ● Jackalax ● Karate Carrot ● Launcher Locust ● Lumbering Elderwood ● Mana Tick ● Ninja Pumpkin ● Piercing Seer ● Raging Goliant ● Rapscallion ● Roaming Bloodmane ● Rumbling Terrasaur ● Scissor Scarab ● Shaman Broccoli ● Silver Fist ● Sniper Mosquito ● Splinterclaw Wasp ● Spore Siren ● Striding Hearthwood ● Steel Hammer ● Terradragon Regarion Doom ● The Great Arena ● Thorny Creeper ● Three-Eyed Dragonfly ● Transforming Totem ● Xeno Mantis
Bronze-Arm Champion ● Bronze-Arm Sabertooth ● Carnivorous Dahlia ● Chief Thorn-Bringer ● Copper Locust
Headstrong Wanderer ● Prickleback ● Razorhide