When first confronted, Mortamor appears to be an old demon with gold orbs levitating before each of his hands. Mortamor himself states that this is merely a facade and will, upon first defeat, emerge from the two fused golden orbs as a hulking, winged demon with spiked shoulders. When this form is defeated Mortamor will literally cast aside his body, becoming the disembodied demonic face and pair of hands he is best known as.
Mortamor is similar to Zoma in that he influences the world through proxies, preferring to revel in the suffering of the humans trapped in his living nightmare than do his own dirty work. Mortamor's plans are more precise than his Erdrick trilogy counterpart, however; rather than sending one lieutenant to cause undirected chaos, Mortamor uses four agents to target specific bastions of the mortal realm that would inhibit his conquest. By sealing away Alltrades Abbey, Medford's Manor, Sorceria, and Cloudsgate Citadel, Mortamor displays a keen understanding of the capabilities of humans and their potential to overthrow him should he attack directly.
Personality-wise, Mortamor is extremely arrogant, condescending and egotistical, even in comparison to the other Demon Lords of the franchise. He does not view the party as threats whatsoever, even after they overcame his numerous assets. Even upon defeat, Mortamor remains in denial of the party' powers up to his last breath. When confronted by Nokturnus, Mortamor drops his narcissistic persona and expresses fear of being challenged by a stronger being but recklessly engages him in combat nevertheless.
Occasionally acts twice per round. Disruptive Wave Fires off a ball of frigid ice. (124~134 ice breath damage to entire party.) Meditation Energy Balls (attack/2 +67, attacks twice) Cackles insanely and launches an attack. (125% damage) Throws a ball of searing flame. (168~188 fire breath damage to entire party.) Venom Mist
In his initial form, he appears as demonic old man with golden orbs. Using the orbs, he can roast the party with searing flames (168~188) or lacerate them with frigid ice (124~134), both of which ignore Insulatle and can only be reduced by armour resistances or defending. His attack while he is cackling insanely increases his strike's power by 25%, and damage dealt with the energy orbs adds +67 to each strike. The orb can potentially strike a single character twice and the added damage cannot be reduced, even with defence.
In this form, Mortamor transforms into a large, hulking demon. He relies mainly on hard-hitting physical attacks, sometimes augmenting himself with Oomph and Buff. When he charges a character, his spiked shoulders will deal 150~180 damage ignoring Defense. He is still immune to status ailments, but his elemental resistances have fallen. After defeating this phase, Mortamor discards this body and emerges in his iconic form.
At this point, Mortamor appears as a disembodied head and two claws. The claws are independent targets that act on their own, and can revive other parts as needed. In order to restore peace to the world, all parts of Mortamor must be destroyed.
The head is very resistant to elemental damage, with all but Frizz and Zap dealing 40%. It can fight defensively with Lullab-Eye to send a character to slumber regardless of Snooze resistance, or go on the offensive with defence-ignoring skills like Pyre o' Fire and Ferocious Roar (120~150). Once the head drops to half health, it will hit the party with Magic Burst for 200~220 damage, and follow up with a meditation that completely restores his MP. The head is also classified as a Zombie-family monster; exploit this weakness with Undead Undoer and Pearly Gates.
Mortamor's right claw appears with his third form. It's much slower than the other two parts, but has the ability to heal the others. The claw is less resistant to elements, taking full damage from everything but fire, wind, and ice. Talon Slam will deal +150 more damage than a normal strike, and Powerful Thrust works the same as Knuckle Sandwich.
Mortamor's left claw appears with his third form. It's much faster than the other two parts, and can revive them with Kazing if it isn't removed first. Claw Slash will deal 25% more damage than normal. This hand is the most resistant to elements, taking full damage only from Zap.
Moratamor appears as a Legacy Boss, obtained after completing Quest #158 (or received at special events). He will become enraged once his health drops to orange range. Mortamor is unique among bosses in that he is accompanied by two enemies that are not found anywhere else, unlike Hootingham-Gore and Shogum, who are accompanied by common monsters. He is also unique among Legacy Bosses in that he is the only one who attacks a single time per turn (but the accompanying claws equate to one or two extra actions, depending on whether one or both are present).
DeathMore is present in all of his forms from VI, though his hands are part of his final form now and not separate monsters. The player will have to obtain nearly all other members of the boss family to breed all of his forms. He is also the boss of Old Man's Gate and is considered by the residents of GreatTree to be the strongest of the evil lords.
The ultimate form of this ferocious fiend. He manipulated men's dreams to further his ambitions of ruling mankind from his home in the dread realm, the fissure between the worlds of reverie and reality
Mortamor's first form appeared on three separate cards. He first appeared as a legend rare card in the 3rd pack, "Phoenix and the Ringing of the Earth", as well as appearing on the skill card for Evil Prayer. When the app's name changed to Rivals Ace, he returned again in the third card pack on a card entitled "Mortamor, King of the Dread Realm". Due to the game's end of service, Mortamor's other forms never appeared in the game and his place is taken by Nokturnus as the final boss of Mortamor's Dreadlair in the Solo Battle Adventure mode.
All three of Mortamor's forms appear as S-rank members of the ??? family as part of the limited Dragon Quest VI event. His Old King form is faced in Chapter 5, Episode 2: Mortamor 1, while his hulking demonic second form, known simply as Mortamor, is faced in Chapter 5, Episode 3: Mortamor 2, while his final Archfiend form and is faced in Chapter 5, Episode 4: Mortamor 3, along with his Right and Left Hands.
His Old King and Archfiend forms can be faced in the "Free the Phantom Realm!" and "Mortamor's Challenge" boss battles, as well. Old King Mortamor appears on his own banner alongside Demon-at-arms and he can participate in the Low djinks's Battle Road as a party member.
Due to Mortamor being able to use Magic Burst, it is likely that he had Gracos seal away Sorceria so he would be the sole individual capable of casting the devastating spell.
Unlike the other Demon Lords in the Zenithian Trilogy, Mortamor was given no further explanation as to his origins or personality in the remakes. However, Mortamor's origin was revealed in the Dragon Quest Monsters+ manga series.
It is reasonable to assume that Mortamor's yellow orbs are his source of energy, due to the fact that they are used to transform him. In Tact, they are known as the Narrow World Orbs, referencing his Dread Realm being a fissure between the Real and Dream worlds
It appears that Mortamor has some unknown history with Nokturnus.
In spinoff games such as Super Light, Mortamor is given various titles in order to differentiate which form he takes. In his first form, he is known as the "King of the Dread Realm" (狭間の王, Hazama no Ō) and the "Old King" (老王, Ro Ō). His second form is known as the "King of Wrath" (憤怒の王, Fundo no Ō) while his third form is known as the "King of Dreams" (夢幻の王, Mugen no Ō) or the Archfiend (大魔王, Daimaō).
