Editing Rex

|caption        = [[File:XenobladeSymbol.svg|50px|class=invert-dark]]

|lastappearance = ''{{iw|xenoserieswiki|Xenoblade Chronicles 3: Future Redeemed}}'' (2023)

Rex is a 15-year-old salvager from {{s|xsw|Letheria}} who lives on a {{s|xsw|Titan}} named [[Azurda]], who he refers to as "Gramps". He unwisely takes on a high-paying mission to help a group of mysterious individuals looking for specifically Leftherian help with searching for a great treasure. They succeed in dredging up an {{iw|xsw|Ancient Ship}}, aboard which is their target, a legendary {{iw|xsw|Blade|XC2}} caled the {{iw|xsw|Aegis}}. Rex foolishly touches the red sword, so the group's leader {{iw|xsw|Jin}} immediately kills him, and the group's muscle {{iw|xsw|Malos}} prepares to kill the rest of the salvagers to cover their tracks. Rex then finds himself in a dream of {{iw|xsw|Elysium}}, the fabled paradise atop the {{iw|xsw|World Tree}} he and many others want to visit, and meets with [[Pyra]], the personification of the Aegis. She says they've been bonded, and she can revive him as her {{iw|xsw|Driver}} and thus wielder of the legendary sword, so she can return to the real Elysium. Rex agrees, and together with the defecting [[Nia]] and {{iw|xsw|Dromarch}}, escape the now-villainous group. In the process, Azurda is wounded, and manages to regenrate himself into a larval form that tags along inside Rex's helmet. Rex makes it his goal to bring Pyra to Elysium at any cost.

As the party travels, Rex encounters Jin and Malos several times, as they try to capture Pyra for their own reasons. This results in revealing [[Mythra]], the original form of the Aegis, who created the alternate personality of Pyra in shame for her actions in the war five hundred years ago. Eventually, Rex connects with both Pyra and Mythra well enough that their trust produces a third form, {{iw|xsw|Pneuma}}, who is able to bestow Rex with additional "Master Driver" powers over Blades and the world at large.

In the course of his adventure, Rex becomes the figurehead of his party of paradise-seekers, each with their own reasons for following him and his optimistic goal. He starts out fairly naïve and all too confident in himself to solve every problem, but eventually learns that he can't do everything and must leave something up to others.

In {{iw|xsw|Xenoblade Chronicles 3: Future Redeemed}}, Rex, alongside {{iw|xsw|Shulk}} leads the {{iw|xsw|Liberators}} against {{iw|xsw|Moebius}} on {{iw|xsw|Aionios}}. In the intro, he, Shulk and {{iw|xsw|Z}} attempted to stop {{iw|xsw|Alpha}} from destroying the world, but loses, resulting him in losing his left eye. He and Shulk later aids {{iw|xsw|Matthew}} in saving his sister {{iw|xsw|Na'el}} from Alpha's clutches and manages to defeat him within {{iw|xsw|Origin}} and became its avatars, alongside Shulk and {{iw|xsw|A}}.

Rex was considered for the initial roster alongside other prospective characters like a character from {{uv|ARMS}}, and {{uv|Pokémon}}'s {{pkmn|Decidueye}}; however, he could not be added due to ''Xenoblade Chronicles 2'' being announced after character planning finished in 2016. As an offered alternative, Rex appears as a costume for the {{SSBU|Mii Swordfighter}}. [[Azurda]] (otherwise known as Gramps) in his miniature companion form appears in the set's outfit. The costume comes as a free bonus with purchase of the [[Fighters Pass]] Vol. 1.

*Like [[Creeper]] and [[Arsene]], Rex has an internal codename. However, unlike those two, Rex essentially has two codenames, that being "diver" and "element". "diver" referencing his job as a salvager and "element" being a generic word most likely to describe Pyra and Mythra's powers, that being fire and light respectively.

**Rex is referred to "element" in a folder containing his model, and is referred to as "diver" with his actual model. "element" is also the codename for Pyra & Mythra's victory theme, and the duo's codename when they are a pair.