Which 1999 Fire Emblem game was first released through the Super Famicom's Nintendo Power flash cartridge service?

The 1999 Fire Emblem game first released through the Super Famicom’s Nintendo Power flash-cartridge service was Fire Emblem: Thracia 776.

Developed by Intelligent Systems and published by Nintendo, Thracia 776 was originally distributed on September 1, 1999. Players could have the game written to a Nintendo Power flash cartridge, a rewritable format offered through participating Japanese stores. A pre-written cartridge was also sold as part of a special DX Pack.

The standard Super Famicom ROM-cartridge version followed on January 21, 2000. That release timing is the key to the question: Thracia 776 was not merely compatible with Nintendo Power; it debuted through the service before receiving a conventional cartridge release.

The game is set in Jugdral during the events between generations of Fire Emblem: Genealogy of the Holy War and follows Prince Leif’s struggle to reclaim his homeland. It is sometimes described as the series’ fifth or sixth entry because numbering conventions differ. It also remained Japan-exclusive, although fan translations later made it accessible to English-speaking players.