After the incident with King Leo, Maya suggested that the party should split up because a rumor spread about a group of five people roaming around Sumaru City suspected to be terrorists, which was most likely to be Tatsuya and the rest, and decided to regroup at the Kuzunoha Detective Agency. After Tatsuya and Lisa arrived together, they found Eikichi and Yukino already there and "Maya" arrived shortly after.
When the party decided to go to Mt. Iwato at Lisa's request, "Maya" began to act strangely by saying things that didn't match her personality when they saw past events on each Mirror Spring. Yukino was the first one to notice this, but ignored it. When everyone reached the last Mirror Spring they saw how "Big Sis" was locked up by the kids in the Alaya Shrine. When Lisa interrupts the event, "Maya" attacks the party, telling them that she was Big Sis and how she hated them because of the hell she went through and that they will suffer the same terror that she had to. When she is about to strike and kill Tatsuya and the others, another Maya blocks the attack.
The other Maya tells them that the Maya that attacked them was an impostor. Said impostor revealed herself as Maya's Shadow. Joker appears saying that the plan of killing them failed. Maya tries to talk to Joker, revealed that he was actually Jun Kurosu. She tried to convince Jun that she didn't die in the fire caused by Tatsuya Sudou so he doesn't have to suffer anymore on believing that she did. Jun yelled that that wasn't possible because Tatsuya killed her, Maya then says that Tatsuya and Jun shouldn't fight anymore and tried to remind him of the promise the two of them made of protecting Maya no matter what. Jun fell to his knees clutching his head in pain and ordered the Shadow to kill her.
After the battle ends, the Shadow didn't understand how Maya can be so strong if she was so eager to die, but Maya denies this last statement by telling that the Shadow is wrong and says goodbye to it.
Unlike Innocent Sin, Shadow Maya wasn't created by rumors but by Nyarlathotep to taunt Maya and the others. She first appears in Monado Mandala with the other Shadow Selves created by Nyarlathotep taunting their real selves.
When the party arrives at the World of Conviction they see Lisa. Tatsuya tries to set her free but Shadow Maya and Shadow Baofu prevents him from doing so and attacks the party. The difficulty of this boss battle depends on the decisions the party makes in the Room of Knowledge and the Room of Emotion.
After the battle ends, the Shadows disappear and Lisa is set free, Tatsuya then begs Philemon to take Lisa back to the real world which Philemon does instantly.
Unlike Katsuya, Ulala and Baofu, Maya's darker side (either the Shadow Self or the reverse Persona) is not present in the scene. Nyarlathotep will ask Maya first if she feels angry. Choosing "at you" will instantly end the conversation, increase the level of Shadow Maya later and bring up the flag for awakening Lisa. If Maya says she is sad, Nyarlathotep will make fun of Maya's feelings for Tatsuya saying that she can never have Tatsuya and continue to urge Maya to pull the trigger and shoot him. Shooting Nyarlathotep is the "wrong" choice as well and instead, the bullet will hit Tatsuya (his HP after this event will drop to 1).
In Innocent Sin, Shadow Maya is a fairly challenging fight, due to her resisting every type of Elemental Spell. As such, it is highly recommended that players utilize Physicalfusion spells against her. One should heal at the beginning since all the other characters except for Maya will have half HP. The Pegasus Strike fusion spell (any Wind Spell + Sonic Punch) in particular is very useful, as it deals High amounts of damage in comparison to other Physical fusions. Sonic Punch is easily obtained on either the Minotaur or Jack Frost Personas (the latter of which also drains Ice damage, which is a direct counter to Shadow Maya's most powerful Spell). Equip either on Eikichi and have him initiate the fusion (as his attack is almost guaranteed to be the highest at this point).
The other party members should focus primarily on support; Maya healing with Media and the others either healing with items or attacking if there is time. Her most threatening spell is Diamond Dust; a powerful Ice attack that hits everyone and has a chance of Freezing. This attack can be deadly, especially if the party is equipped with the starting set of Personas exclusively, as both Tatsuya and Yukino will be weak to it and are likely to fall quickly. As such, it is recommended that the party either enter the battle with no Personas that are weak to Ice, or simply have anyone weak to Ice defend for the majority of the battle. Her unique spell, Dark Dimension, deals an instant kill to a character if it hits. Unlike Maya's Omni Dimension, this spell has a 75% chance to hit a character, so it's good to have numerous reviving items handy. Mahama, a Light-elemental fatal attack against the whole party, can be negated by the spell Tetraja (found on Personas such as Surya and Airgetlam) or the Silver Manisha item. Either should be re-applied after Mahama is negated or any ally is killed and revived.
In Eternal Punishment, Shadow Maya, due to using Reverse Artemis, is weak against Physical attacks and reflects magic attacks. Tatsuya and Ulala are a good choice to attack her with either a strong Physical attack like Apollo'sGigantic Fist or with a regular attack unless she uses the spell Tetrakarn that makes the wearer reflect one Physical attack. Shadow Maya will use Eclipse Mirror, it may deal a great amount of damage but it can be healed with one Mediarama if Maya is still active. She also has Mediarama to heal herself and Shadow Baofu, but she doesn't cast this spell often.
In the case of Shadow Baofu, he is strong in Physical attacks but weak to Electric attacks. His most dangerous attack is Level Trap, which damages all characters based on level; the character with the highest level is killed instantly, so be sure to have a Persona with a reviving skill or numerous reviving items. Again, a regular Electric attack or a fusion spell is required for him.
Since Shadow Maya can reflect all magic damage, it is not recommended to use any all-enemy magic spell or fusion spell.
The way Maya faces her Shadow in Innocent Sin is the most special one among the rest of the playable characters (including those from Persona 4) in that Maya has never admitted her Shadow is a part of her, but is always denying it even after her Shadow's defeat because she does not want to admit that she hated the kids for the incident ten years ago.
Since the shadow is supposed to be the hidden side of one's self, what Shadow Maya says could be partially true, albeit somehow twisted. Maya does resent her childhood playmates, but the cause could not be the arson because the culprit was in fact Tatsuya Sudou. Maya is unconsciously aware of that from the resonance of the Persona. What she resents could be the kids' obliviousness of their memory of ten years ago. This is supported by the fact that she approves and sides with Joker (Jun) for remembering her all along.
When Shadow Maya disguises herself as the real one, apart from her out-of-character dialogues, there are a few more things that hint the inconsistency.
When she enters Kuzunoha Detective Agency, Tatsuya Suou stands back a little from her instantly, probably out of surprise or fear.
When the group is teleported into Philemon's realm, she instantly does her defending pose against Philemon. Philemon also does not speak or face to her during the conversation.
Her sprite and portrait are slightly different, with more shadows on her face along with red eyes. The PSP version of Innocent Sin also alternates her new portraits in her status section and cut-in used for Fusion Spells in similar ways.
She will refuse to participate in any contact with demons during battle. Any contact combo with her will be commented as "awkward."
Before finishing the Mt. Iwato dungeon, the party can collect and spread a rumor about Kuchisake-Onna. The rumormonger testifies that the woman in question mumbled to herself a lot, saying "I wonder if this costume's too obvious..." and "Has Tatsuya-kun reached the detective agency yet?" This implies that the real Maya is wearing a long coat in order to avoid attention because of her Shadow's activity.
Similar to the protagonist of Persona and Tatsuya Suou, Shadow Maya is featured alongside the real Maya in the Japanese box cover. While the real Maya is weeping and holding the ruptured Apollo's mask in her hands, Shadow Maya is sneering and holding Tatsuya's head.