- For fighter info, see Pyra/Mythra (SSBU).
Pyra and Mythra are the human personifications of the legendary Blade Aegis, which is used by their Driver Rex. The girls form a special bond with Rex and share a life force with him, meaning if one were to die, the other will follow suit. The pair consider themselves sisters, having the ability to mentally communicate with each other through a psychic link. They are also capable of switching into each other freely whenever the need arises.
Though the two are technically the same person as they are the same blade, their personalities are polar opposites. Pyra is depicted as a very timid, soft-spoken, and deeply kind woman. Mythra, on the other hand, is very reckless and rude with a short temper. However, both share their own set of insecurities, which drive them to continue on with their journey to Elysium alongside Rex and company.
Prequel (Torna - The Golden Country)
In the year 3564, a priest named Amalthus climbed the World Tree to reach Elysium in the hopes of finding the divine deity known as the Architect, believing they hold the answers to his beliefs on the corruption of humanity. Upon arriving, he instead discovers the area empty; however, he finds two Aegis Core Crystals from the Trinity Processor and steals them as proof of his journey for the citizens of Alrest.
Upon descending from the tree, he awakens one of the cores first, named Malos, and the two form a bond. However, fueled by Amalthus' hatred of the world, Malos disconnects from him and soon begins a destructive assault on all of Alrest. Amalthus is then warned that he is not capable of awakening the second Crystal, so he recruits Addam, the prince of the Kingdom of Torna, to do it for him. This Crystal is revealed to be Mythra and the two quickly form their own bond and begin their quest to stop Malos and break his seal with the Tornan Titan while meeting and rescuing new allies along the way. These several clashes between Mythra and Malos that proceed through the rest of story would come to be known as the "Aegis War".
Eventually, the party have a final stand against Malos on both the sky and the ground, with Mythra taking control of the giant Artifice mech Siren. During the final battle, Malos taunts her into using her full power, breaking her bond with Addam; in the ensuing chaos, Mythra successfully wounds Malos' core Crystal, but destroys the Tornan Titan, the town of Auresco, and the entire Kingdom of Torna in the process. Witnessing all of the destruction and lost lives, Mythra, in her moment of extreme grief, spontaneously transforms into Pyra as to never use any of her chaotic abilities ever again and tasks Addam to seal her body in a ship and sink it underneath the Cloud Sea, never to be seen again.
500 years later, an orphaned salvager named Rex and his fellow Drivers Jin, Malos, and Nia from the organization called Torna are tasked with scavenging an ancient ship for parts, which is revealed to have been the one containing Pyra's sealed body. Rex accidentally touches Pyra and the Aegis, but Jin fatally stabs him. Rex then awakens inside Pyra's memories of her old home in Elysium; she asks him to take her back there in exchange for his revival through half of her Core Crystal and becoming her Driver, to which Rex agrees. Rex awakens in the real world and the two fight their way out of the ship alongside Nia and her Blade Dromarch, who have since defected, and escape Torna with the help of Rex's Titan companion Azurda. However, Azurda sustains injuries and ends up reverting to his larval form as they crash land on Gormott, but not before telling Pyra that he recognizes her as Mythra's counterpart.
The group soon travel to Torigoth, where they recruit the Nopon Tora and his Blade Poppi as well as rescue Nia and Dromarch, who have been apprehended by Mòrag and Brighid and the Mor Ardain soldiers. They also defeat several enemies as Pyra starts to get recognized as the Aegis for her Core Crystal. After escaping, the party soon hijack a Titan ship to sail straight towards the World Tree. On their way there, they are ambushed by the Ophion, an Artiface previously controlled by Mythra. The group try to evade it only to end up swallowed by the Titan Uraya. Inside, the group encounters mercenary Driver Vandham, who then attacks Rex as a test of skill; impressed, he then joins the party and lets them stay in Garfont Village with him. It is here where the group learns about the events that occurred 500 years prior as well as Malos and Jin's true identities and intentions. However, they are soon ambushed by Akhos and Obrona, two members of Torna who have come to kidnap Pyra. After a fight, the party escapes to Fonsa Myma and meet Cole, one of Mythra's former allies during the Aegis War and Amalthus' former Blade, who instructs them on how to reach the World Tree. While there, Malos kidnaps Cole's adopted granddaughter Iona and sends a telepathic message to Pyra, telling her to meet him alone in the Olethro Ruins to rescue her.
In the morning after, the party go off in search of Pyra after discovering she's gone missing. Chaos ensues upon their arrival, where Rex attempts to fight Malos himself only to be rescued by Vandham's noble sacrifice. Rex however fails to escape and, in a last ditch effort, Pyra transforms into Mythra (to the surprise of everyone) and uses Siren to destroy Obrona and Malos' Blade Sever. Furious at her actions and Rex's recklessness, Mythra transforms back into Pyra, who then explains everything.
As the group continues to find a way to evade Ophion, they run into Mòrag and Brighid again, who join the party after assisting them in stopping the sale of artificial Blades. They later encounter Zeke, the prince of the Kingdom of Tantal and an envoy of the Indoline Praetorium, who joins the party. Upon their arrival at Tantal and after talking with Amalthus, they encounter the Omega Fetter, the control unit of Ophion which Mythra fixes. Unfortunately, Jin and the rest of Torna arrive to ambush the group. During the ensuing battle, Mythra attempts to shoot Jin with a Siren beam but he is able to deflect it; in retaliation, Mythra transforms back into Pyra and aims the beam for herself, using it as a bargaining opportunity knowing that Malos will need her alive. Jin relents and takes her, sparing Rex and company.
Pyra is taken by Malos and Jin to the Cliffs of Morytha, where Malos proceeds to enter her mind and steal her memories to regain his strength. The party, however, arrives and quickly intervenes to save Pyra. Rex, now fighting without the Aegis, sees a vision of both Pyra and Mythra amidst the chaos and tell him to leave their body behind to die, as it was their original intention to return to Elysium. Rex refuses, saying he is fighting for them instead; this declaration combined with his deep bond with the girls results in Rex unlocking their true form, a blue haired girl named Pneuma, and Rex unlocking his power as the Master Driver. With this newfound ability, Rex finally gains the upper hand against Jin, forcing Malos to summon Ophion, who knocks the party down to ruins of the town below.
In the Land of Morytha, the group and Jin are ambushed by Amalthus, who has gained control of various Titans. Jin sacrifices himself to defeat him, but not before the priest exterminates all members of Torna save for Malos. The group then begin their ascension of the World Tree; upon arriving at Elysium, they discover it has become a barren wasteland, but still inhabited by the Architect, who in actuality is a scientist named Klaus. He explains that he discovered a device (being the Trinity Processor) that is capable of sending objects into different dimensions, but its side effects caused his body to split in two and destroyed the old world.
Klaus, knowing he is going to die soon, tasks the group with killing Malos once and for all, who has now obtained the Artifice Aion, a giant mech capable of destroying all of Alrest. The party eventually prevails against Malos and kills him, while Klaus also passes at the same time, but not before he gives Rex and company "one final gift". In the end, Pneuma sacrifices herself to detonate the World Tree as the world starts to crumble and the Cloud Sea of Alrest begins to fade away; as the Cloud Sea parts, it reveals the Titans having merged to form a new landmass on the neverending ocean below, signifying the rebirth of a new world. Upon returning to Alrest, Rex resonates with the Aegis Core Crystal Pneuma left behind again (which has given him his full heart back); to his surprise, Pyra and Mythra are revived in separate bodies, and with encouragement from Nia, Rex walks over to them to reunite.
Pyra and Mythra are capable of swapping into each other freely in a similar vein to Zelda and Sheik pre-Super Smash Bros. for Nintendo 3DS and Wii U; as such, the two have differing stats as well as unique Special Moves while still sharing a slot in the roster.
Prior to their inclusion, Pyra and Mythra had already appeared in Ultimate's base game as collectible Spirits, both of which are under the Support class. The song "Still, Move Forward!" will play on both of their Spirit Battles.
Pyra's Battle uses Lucina, who will start the battle with a powered up Fire Bar and is assisted by Shulk (meant to represent Rex) who is under the Curry effect. The stage is the Battlefield form of Halberd, which is meant to represent the Ancient Ship she was found in, and the floor is covered in lava.
Mythra's Battle uses Corrin, who will start the battle with a Beam Sword, and is also assisted by Shulk. Corrin's Final Smash will also be amplified once the Final Smash meter is full. The stage is the Battlefield form of Gaur Plain.
Added in the girls' Challenger Pack is a Spirit of their true form Pneuma, who is also in the Support class and is assisted by Shulk in her Spirit Battle. Pyra and Mythra themselves are used for the battle and will periodically turn Metal as well as suddenly activate any of their Final Smashes at a random time. It is a Stamina match and it takes place on Cloud Sea of Alrest, with the song "Counterattack" playing.
- Pyra and Mythra are the fourth swapping characters in Smash, following Zelda and Sheik, Samus and Zero Suit Samus, and the Pokémon Trainer.
- Of the four:
- They and the Pokémon Trainer are the only ones to remain swapping characters for Super Smash Bros. Ultimate.
- They are the only ones to share the same voice actor
- Of the four:
- Pyra and Mythra are the second most-recently debuted fighters in Smash, as Xenoblade Chronicles 2 was released in December 2017.
- Pyra and Mythra have the second shortest duration of time of being introduced in Smash in a non-playable capacity and eventually becoming a fighter, at 2 years and 2 months, due to the fact that they appear in the base game already as Spirits.
- Pyra and Mythra are collectively one of six characters to have never appeared on a handheld system prior to joining Smash, the others being Wii Fit Trainer, Bayonetta, Inkling, Dark Samus, and Min Min.
- To keep with Ultimate's E10+ rating, Pyra and Mythra's clothing designs have been redesigned from their original more revealing versions, which first appeared in their Spirit artworks.
- Mythra's redesign would later be made available in Xenoblade Chronicles 2 as part of a free update, being called "Massive Melee Mythra".
- The artwork of Pneuma used for her Spirit was custom made for Ultimate by Xenoblade Chronicles 2's character designer Masatsugu Saito, as any form of official art or render for her was never made prior.