Echelon Siren

Echelon Siren often refered to as Sirens are a type of Artifices in Xenoblade Chronicles 2. They were originally used to defend the World Tree. After the fall of mankind, the Aegises that were originally the central computer of the Beanstalk retained control over them and the other Artifices.

History
In the year 20XX, the Beanstalk was attacked by the Saviorite Rebels. The Echelon Sirens that defended the space station were easily overpowered by the myriad of Artifice Colossus controlled by the rebels. This leads the director of the Beanstalk to order the activation of Artifice Aion, though Klaus hijack the Trinity Processor and use it to control The Conduit and create a new universe. This teleports most of the persons that were around the Beanstak in alternate realities and marks the fall of mankind. After that, the remaining Sirens were left unused for millennia.

When Amalthus arrives at the top of the World Tree, he takes the two cores of the Trinity Processor that remained in this dimension back with him and awaken Logos as Malos. Malos realise that he has control over the Artifices and driven by Amalthus' desperation he start to use his Siren to destroy Coetia. Pneuma is awoken as Mythra soon after by Addam Origo to stop Malos. malos grows tired of letting Siren destroy Titans by itself so he decide to use Gargoyles to make the core of Torna explode. both Malos' and Mythra's Siren are used during their battle at The Soaring Rostrum and after a while, both aegises decide to directly control their artifice, which cause fatal damages to the Titan and kills a lot of its inhabitants including Milton. Malos' Siren is destroyed by Mythra soon after and Malos is left for dead.

When Mythra awakens for the first time in 500 years at the Olethro Playhouse, she uses Siren's power to send blasts of light down on Akhos and Malos. This causes their Blades, Obrona and Sever, to revert back to their Core Crystals. Mythra tells Rex that she cannot use Siren's power indoors, as it would result in the structure collapsing. She uses Siren's power again at Bulge Harbor to revert Mikhail's and Patroka's Blades to their Core Crystals as well.

When Jin unleash his true power at Genbu Crown, Mythra tries to useSiren to stop him but his control over elementary particles allow him to stop the beam of Ether right on its track. Jin then defeat the party and as he is about to kill them, Pyra uses her willpower to control Siren and uses its targetting ray to take herself hostage and threaten Jin that she will destroy herself with it if he kills the party. Jin says that he would just stop the ray to which Pyra respond that the ray is not made of Ether but pure light and thus too fast for Jin to stop it.

After Pyra and Mythra become Pneuma at the Gotrock Oracle Ruins, Malos summons Artifice Ophion to attack the party. Pneuma then summons Siren to fight Ophion, the battle destroys the ruins and sends the party into the Land of Morytha. Siren won the battle, and Ophion broke free of Malos' command and stopped guarding the World Tree.

Upon reaching the exterior of the World Tree, Amalthus, using Fan la Norne's Core Crystal that he implanted in himself, attempts to control Mythra and summon Siren to attack Torna, though Mythra resists. With Poppi's help, Rex and Mythra get close to Indol, and Mythra uses Siren to destroy Indol's amplification towers and prevent Amalthus from controlling Blades from such a distance.

After meeting Klaus, Malos takes over all the Artifices found in the World Tree and uses various Sirens and Gargoyles to attack Alrest. After the disappearance of The Conduit, they cease to work and fall down alongside the Beanstalk.

Merchandise
In addition to the Pyra figure previously announced by Nintendo, Monolith Soft has announced the Siren and Mythra figures made into a 1/7 scale respectively by Kotobukiya and Good Smile Company.