Fade was the mobile-exclusive Apex Legends character classified as an Assault legend.
Ignacio Huamaní, known by the callsign Fade, was introduced in Season 1 of Apex Legends Mobile. Unlike the main game’s shared roster, Fade was created specifically for the touchscreen version and was never part of the standard PC and console character lineup. His concept combined high mobility with a technologically advanced combat suit and phase-related abilities.
Apex Legends Mobile also introduced Rhapsody, a second exclusive character. Rhapsody was classified as Support, so she is not the answer to this question. Vantage and Conduit were added to the main Apex Legends ecosystem rather than being mobile-exclusive characters.
Apex Legends Mobile launched for iOS and Android on May 17, 2022, but Electronic Arts shut it down on May 1, 2023. That closure is why the question uses the past tense. Fade and Rhapsody remain important parts of Apex history even though the mobile service is no longer playable.