Praxis is the fighter assigned to the starfighter Tiberius. He was saved by the Reliant's crew during a recent Colteron attack on the Alliance Space Station, however he lost his left eye and his navigator in the battle. Afterward, Ethos was reassigned to the Tiberius. Praxis has unrequited feelings for Abel.
Hamlet has said that Praxis is a year older than Abel, which would put him at 25.
For some reason, Praxis has a "personal dislike for Cain" (in contrast with the other fighters who do not have a problem with Cain).
Hamlet said during a recent March 2014 Livestream that Praxis is the tallest of the characters at 6'2".
Praxis, is defined by Wikipedia as the process by which a theory, lesson, or skill is enacted, embodied, or realised.Ethos, on the other hand, is a Greek word meaning 'character' and in rhetoric, is used to mean a mode of persuasion that appeals to morals and wisdom.
It's also possible that Praxis was named after the Praxis effect, a visual effect sometimes used in explosions in science fiction. The Praxis effect just happens to be illustrated on Chapter 1, page 17 of the comic, right after Praxis was saved.