Royalmon is a Demon Lord Digimon whose English name is derived from Royalty, which signifies his nobility, while his Japanese name and design are derived from the mythological Goryō, a Vengeful ghost from the aristocratic classes and one of the Yūrei. He is one of the founders of the Royal Family, most notably the King of the Digital World. His wife is Queen Majestymon and his children are Valentinemon, Sirenmon, Metaldramon/Signamon and Princessmon. He was created around the time the Digital World was in its infancy.
After being influenced by the evil powers of the Dark Area, the once just and noble Emperormon transforms into one of the most heartless, tyrannical rulers in the Digital World, Royalmon. At first this transformation into this Demon Lord Digimon, wasn't a major cause of alarm, that was until his wife Queen Empressmon also was seduced by the power of the Dark Area, turning her into Majestymon, who was equally as merciless. With his new power, he ruled over the Digital World with swift relentlessness. During his reign, the Folder Continent was invaded by two of Royalmon's secret elite Digimon armies, the Hellenistics and the Cadrians, with many of its inhabitants were enslaved or captured as prisoners of war. These Digimon were then relocated to File Island which was now turned into the Royal Family's main prison after being captured by the Noble Army. It wasn't long until Royalmon had total control over the eastern half of the Digital World. With Royalmon increasing his territory he later set his sights on the Server Continent, quickly invading it, an action that paved the way to years of conflict. With the Server Continent under invasion, the Olympos XII tried to intervene and a bloody war ensued with many Digimon as casualties. In the aftermath of the war, most of the Cadrian and Hellenistic armies were deleted, and the Olympos XII halted the total domination of the Server Continent. The victory in Server proved to be a bittersweet one as they failed to stop Royalmon's stranglehold over the Eastern Digital World and the Folder Continent.
Without his knowledge, Majestymon met with Dianamon, Azulongmon, Cherubimon, AncientGreymon and Alphamon in order to sign a peace treaty guaranteeing that Royalmon and his empire wouldn't invade any more land and File Island would be annexed back to the Olympos XII, Ten Legendary Warrior, Royal Knights, Digimon Sovereigns and Celestial Digimon and the enslaved Digimon imprisoned in the Royal Family's penitentiary be set free. While agreeing to the terms of the treaty, Royalmon secretly staged a rebellion against Yggdrasill with Lucemon and Daemon alongside several Demon Lord, Devil, and Fallen Angel Digimon, but wasn't directly involved. While the other Digimon were were imprisoned in the Dark Area, Royalmon vowed to avenge them. Around this time Majestymon gave birth to Nereidmon and Erosmon, the Crown Prince and Crown Princess of the Digital World. With the birth of his children, Royalmon's quest for revenge was sidetracked but Majestymon had her own choice of revenge when she sent Aphroditemon and Athenamon, two of the remaining members of the Hellenistic and Cadrian armies, to the Royal Base, nearly exterminating the inhabitants and forcefully recruiting the survivors. The news of the massacre proved one again how merciless the Royal Family was, but with no escapees and survivors there was no proof of the crime. His bloodthirst for power grew when Majestymon had two other twins Noirmon and Principessamon and Nereidmon and Erosmon Digivolved into their Ultimate levels, Galenemon and Passiomon after secret training in the Dark Area under the watchful eye of the Seven Great Demon Lords.
Royalmon then came up with one of his most devious plans ever: replicate the data of the Ten Legendary Warriors into much stronger Digimon, he called them the Elemental Gods. This dark plan occurred during the coronation of Galenemon and Passiomon to commemorate them digivolving into their Ultimate Levels, also around this time Noirmon and Princepessamon reached Ultimate levels, Twilightmon and Himemon. He managed to copy the data of AncientTroiamon, AncientMegatheriummon AncientWisetmon and AncientGarurumon during the celebration. With the power of four of the Ten Legendary Warriors at his disposal, Royalmon with help from Majestymon created Sequoiamon, Tundramon and Brightmon and Cobaltmon, the Gods of Wood, Ice, Light and Metal. Wasn't long before he went after AncientKazemon and AncientGreymon, by those actions alone would seal the fate of the Royal Family. Seraphimon and the other Celestial Digimon got wind of Royalmon's evil plans when Blazemon and Aegaeonmon were born. With help from the Royal Knights and other Digimon, the Celestial Digimon attacked the Royal Palace.
Risk of potentially having his youngest children caught in the crossfire, Royalmon and his forces had no choice but to escape to the Dark Area with help from GranDracmon and Plutomon. Royalmon and Majestymon would later leave their four children under the watchful eye of the Seven Great Demon Lords while they reconvene and meet with GranDracmon and Plutomon. While in their absence, they managed to copy the data from the remaining Legendary Warriors with the help of several Bakemon and Devidramon in order to complete their Elemental God army. Noticing the dark dormant power of their youngest son, now a Metaldramon, they gave the Spirits of Darkness to him around the same time he turned into Signamon. The once dictators of the Digital World were reduced to ruling alongside others, while despising this Royalmon used this to his advantage, making many allegiances allowing him to slowly rise to power once again, giving him as much authority in the Dark Area as the Seven Great Demon Lords, GranDracmon and Plutomon.
Due to the hierarchy of the Royal Family, Royalmon has dominion over many of the inhabitants of the Dark Area such as Demon Lord, Devil, and Fallen Angel Digimon. It's said that Royalmon and his family learned how to bypass the "Hell Gate" or "Maw" into both the Digital World and the Real World and World of dreams. The Royal Family to said to have control over the Dark Ocean appointing Dragomon as its overseer.
Royalmon is said to have a human-like features often confusing other Digimon and Humans as a human adult, its this trait that he and his wife have passed down to their four children. He also has the ability to retract his wings and tail into his body, yet another method he passed down to his children. His outfit resembles that of the one worn by the adult version of Richard in Tales of Graces.
- Imprisonment Ball – Royalmon appears behind or in front of the opponent and holds his hand out, ensnaring them in an inescapable golden sphere of energy. Royalmon can manipulate this ball as much as he wants, one example is when he toys around with this containment like a soccer ball, beating the victim around, then kicking the ball away. The ball detonates on contact with anything other than Royalmon himself. The resulting implosion is so immense it creates a vacuum that sucks in anybody near by.
- Manipulation Sorcery – A spell which Royalmon can cast over any being in an effort to take control of their mind. This spell is only known to work successfully on targets with evil in their hearts (only those who are pure good can resist, as even those pure evil, like Akihiro Kurata and Digimon who are of the Virus attribute, are vulnerable to his attack). The attack seems to work on anyone with a single evil characteristic. Even those who are relatively neutral, such as Data-type Digimon and even some Vaccine-type Digimon, are vulnerable. Royalmon has also used this spell to force a Digimon to under go Dark Digivolution, enabling them to be controlled.
- Whirlwind Blow – By lightly blowing, Royalmon produces strong winds that formed a tornado. Then, the tornado lifts the opponent into the air and throws them a great distance away. It's hinted that Royalmon only uses his Whirlwind Blow on feeble opponents.
- Death Storm – Royalmon raises his hand and opens it to release a giant Exploding Wave. While easily avoidable, Royalmon's Death Storm causes large scale planetary destruction and a very large tsunami that travels in a large radius in all directions.
- Repeating Death Beams – Royalmon presses his palms into the earth of the planet he is on and then detonates the entire planet. Causing the ground to rupture and beams of fire to spew from the Earth, soon resulting in the planet being destroyed.
- Emperor's Edge – Royalmon fires a fiery gold and red slashing energy wave at the opponent. As soon as it hits the opponent, a large explosion in the shape of a blade appears, knocking away the opponent.
- Possession – Like her family, Sirenmon is able to merge her body and overshadow or otherwise control another life form. While she has some strength of her own, Sirenmon's combat abilities are best suited to exploiting the full potential of a host body. It appears that when she has chosen a permanent host, she begins to alter the host's appearance to mirror her own (as evidenced by the appearance of Yoshino). After possessing a host, Sirenmon combines their power with her own. She also gains the ability to assimilate the techniques of those who she has possessed. Sirenmon uses this to take control of. Sirenmon uses this to take control of Sora Takenouchi and Yoshino "Yoshi" Fujieda.
- Death Beam - She extends her right arm and fires a small, thin, very fast, and concentrated laser-like beam from either her index finger or her tail, which barrels down and pierces through an opponent.
- Power Up - She has the power to suppress and increase her power.
- Telekinesis – She can lift or move large objects through the air and blow up objects as big as mountains with only her mind.
- Barrage Death Beam - A rapid-fire version of the Death Beam technique.
- Explosive Wave – She bursts out energy from all over her body in order to repel the opponents around her.
- Super Explosive Wave – A stronger version of the Explosive Wave, she releases a gigantic wave of energy from her body, causing a huge amount of destruction.
- Finger Beam - She holds out her index finger and releases an energy beam from her fingertips.
- Scatter Finger Beam - She leans forward and points all five fingers of her right or left hand, then she charges up five small golden-yellow energy spheres each on the tip of each finger and finally fires the energy spheres inflicting a great deal of damage.
- Continuous Energy Bullets or Continuous Energy Waves - She fires many energy waves from a single hand at once at a very rapid rate, which causes a lightning speed effect.
- Magic Materialization – Used to create clothes for herself.
- Shape-shifting – Her and her family have the power to shape-shift into any human and Digimon they have come into contact with.
- Eye Lasers – A thin laser-like beam is shot from both of her eyes.
- Telepathy – She has the ability to channel one's thoughts to another being.