Many of her other skills, both active and passive ones, can grant a party immensely effective regeneration of both HP and SP per turn and even a low-cost way to revive fallen friends with full health. To gain access to some of the most overpowered support skills in the game, players will need to use one of the few recipes available to fuse the magnificent Maria from other personas. These fusions are understandably pricey for such a high-level ally, however, most of the recipes make some sort of sense in regards to lore and game mechanics, which makes learning them a bit easier.
In Christian mythology, particularly Catholocism, the Virgin Mary is seen as one who has ascended into a celestial figure; a queen of heaven. As such, most of Maria's fusions result from gods, angels, and even some demons from all over the world. Futsunushi is one such god from Japan who represents swordsmanship and is the patron of honorable weapon wielders all over the island nation. As one would expect, he boasts excellent Physical skills, including one of the best multiplier-stacking combos in the game thanks to his Will of the Sword trait and Charge skill.
Baal is a Caananite god who represents fertility. Being a deity responsible for healthy reproduction, it makes sense for them to be included as a fusion component for Mary, the mother of Jesus Christ. This powerful figure is mentioned in some Christian texts as a demon, though this is due to the European church vilifying the gods of other cultures throughout much of history. This being holds many strong Wind skills, which are pretty hard to come by, making them a useful member of a party lacking such elemental attack coverage.
Appropriately powerful beings fuse to form Maria here, though they look far more fierce than she. Satan, the antagonistic figure in Abrahamic mythology who tempts mankind with a plethora of sins, is a more lore-suitable fusion material than one will initially assume. Maria's appearance in Persona 5 Royal depicts a stone T-rex beneath one of her legs. In Christianity, Mary is sometimes shown with one of her feet upon a snake or dragon (that represents the devil), which is meant as a symbol for good's victory over evil.
The mighty golden dragon hails from Chinese mythology and is the deity who presides over the center kingdom, flanked by those to the north, east, south, and west. Kohryu is considered the most powerful of all the celestial creatures and represents the element of earth. Their P5R appearance has them wielding some of the most devastating Psychic-type skills, like the severely damaging Psycho Force, as well as buffs that can further increase their potency, such as Concentrate, which massively multiplies the damage of their next magical attack.
Mother Harlot represents lust and depravity in Christian mythology and is essentially the opposite of Maria in every aspect one can think up. This is even reflected in her stats and skills in-game. Whereas Maria has those almost entirely consisting of support and healing skills, Mother Harlot's set pertains to instant death skills and Curse-type attacks. She can even gain a passive skill that repels Bless attacks, the inverse of Maria who absorbs attacks from this element.
The other half of this fusion is a very clear fusion already. Ardha is a deity from Hindu mythology that was birthed from the literal joining of the god Shiva and his wife, Pavarti. Their love was said to be so strong that they physically became a single being. Ardha has a variety of skills, though focuses the most on support. Like Maria, they have the always-useful Salvation skill, which fully restores the health of all party members as well as heals them of all common status ailments.
As a goddess of love, war, and fertility, Ishtar is a pretty lore-friendly fusion material for Maria. This deity from Babylonian mythology also focuses on healing and support skills and reducing their cost, though not to the efficiency and power that Maria does.
Originating in a far more recent source, Hastur is a mighty being from the Cthulhu mythos. Most of the mythos and its Elder Gods spawned from the legendary mind of H.P. Lovecraft, the New England horror and fantasy author. Accordingly, Hastur's appearance in Persona 5 is sufficiently creepy when he shows up as both a boss and a shadow respectively. He focuses on deadly Wind attacks that shred foes as well as rare skills like Spirit Drain, which can siphon SP from individual enemies.
Here two figures of contrasting nature once more fuse to form Maria. Ongyo-Ki is an oni from Japanese mythology who is credited with creating the very first kinds of ninjutsu. They lurk in the shadows and can suppress their presence to take any foe unaware. As such, they have many skills pertaining to decreasing incoming damage and striking adversaries multiple times.
References to Zoroastrianism are rarer in Persona 5 than other mythologies. This is likely due to the most important figures from this ancient religion lacking physical descriptions, though Vohu Manah was still represented. This being is the good thoughts that originate within the human mind as well as the spirits of all animals. With this positive theme, it makes sense that this aspect focuses on healing and support skills. Their passive skill, Invigorate 3, is particularly handy because of the 7 SP it automatically gives the player each turn.
Futsunushi appears once more for a Maria fusion recipe, though this time alongside a god from a very different pantheon. This personification of the sword from the far east can dish out great damage due to wicked multiplier combos, as stated before, though his best method of delivering this damage is with his skill Brave Blade, which does colossal damage to a single foe in addition to having an enhanced critical hit chance.
The Allfather from Norse mythology, Odin, may not be equipped with very impressive Physical skills, but he has a wealth of mighty Electric ones. His Thunder Reign and Wild Thunder skills can wreck individual and all foes respectively with severe damage. He also has a trait and some passive skills that decrease the cost and increase the power of his Electric skills.
Here two figures from Buddhist mythology combine in another dynamic recipe. Mada is a mighty monster once summoned by a selfish sage to threaten the gods themselves. This beast was said to have a mouth so massive that it could eat the world and sky in one bite. They have understandably destructive skills, though those pertaining to the Fire element.
Conversely, Zaou-Gongen is a deity who protects the mountains of Japan. They have the skill God's Hand, which unleashes colossal Physical damage onto a single unlucky target. With his skill, Undying Fury, this already powerful attack has its damage increased by 30%.
Some may be confused by both Satan and Lucifer appearing as different personas with no in-game relation. There is a ton of debate about whether the two are the same or not in Christian lore, however, the game developers who worked on the Persona series have defined this controversy in their own way by each being's in-game text. Satan is described as the snake sent by the Abrahamic God to test mankind's faith, whereas Lucifer is the fallen angel who rebelled against God and was subsequently cast down into the abyss of hell.
To balance out the fell energy in this fusion, there is the archangel Raphael. This winged warrior of heaven is one of the Abrahamic God's four highest-ranking angels and has a skill set that acknowledges this strength. He has a colossally damaging Physical skill in Sword Dance, though his support and passives are what make him truly strong. He has a host of said skills that can increase Physical damage, increase experience gain, half the cost of Physical skills, and more.
Two mighty gods from vastly different mythologies merge here to form the divine Maria. Chi You, the god of war from Chinese mythology, is known for inventing and wielding an armory worth of weapons. Usually depicting holding many of these armaments, this is reflected in his Persona 5 appearance in that he can unleash both Physical and Psychic attacks to great effect.
Odin returns in this fusion recipe as another godly component. As one of the best magically-oriented offensive personas, his Electric attacks are always great to have around. Though, he also has some nice utility due to his passive Fast Heal skill, which cuts the time needed to recover from status ailments in half.
Not only is this the most expensive fusion recipe for Maria that is possible, but it is also arguably the most appropriate. Lucifer has a combination of the best passive defensive skills in the game, like Repel Bless, which makes him immune to his only weakness, and Drain Phys, which is an overpowered max-level passive that allows him to absorb all Physical attacks launched against him. This combined with his already numerous elemental resists and blocks make him incredibly hard to take down.
Counteracting Lucifer is the loving and fertile Ishtar. Much like Maria, her motherly nature and light-emboldening lore make for an excellent symbolic triumph over evil. Since she has many skills that can be of great effect when used by Maria, one should try to inherit some of them when fusing the Mother of God for an even more powerfully benevolent persona.