Data miners have uncovered voiced battle lines and internal character data for figures like Rhea or Arval, but these remain "secret" characters unlockable through in-game New Game Plus or Renown rather than external DLC.
While officially launched on June 24, 2022, your query refers to a specific file format ( .nsp-dlc.rar ) commonly associated with custom firmware and Nintendo Switch emulation communities. Fire-Emblem-Warriors-Three-Hopes-nsp-dlc.rar
The Harsh Reality About Fire Emblem Warriors: Three Hopes DLC Data miners have uncovered voiced battle lines and
Official sources and community discussions confirm that Nintendo never released additional paid downloadable content for Three Hopes . Fire-Emblem-Warriors-Three-Hopes-nsp-dlc.rar
Official development for the game concluded without any major story expansions or character DLC.