Short answers, pulled from the story.
Final Fantasy: Legend of the Crystals is a 1994 original video animation that serves as the first direct sequel to the video game Final Fantasy V. The story unfolds on Planet R two centuries after the original game and follows a new generation of heroes including Prettz and Linally. The series was produced by Madhouse and released across four thirty-minute episodes between March and July 1994.
The true antagonist of Final Fantasy: Legend of the Crystals is the wizard Ra Devil who seeks to steal the brain of Cid to unlock the secrets of the four crystals. Ra Devil assumes his true form only after successfully acquiring the knowledge contained within the stolen organ. The shadowy Deathgyunos serves as a rising evil that steals three of the four crystals but is not the primary villain.
The first volume of Final Fantasy: Legend of the Crystals was released on the 9th of December 1997 containing the Wind and Fire chapters. The second volume arrived on the 3rd of February 1998 covering the Dragon and Star chapters. A boxed set combining both volumes was later released on the 17th of November 1998.
The musical score for Final Fantasy: Legend of the Crystals was composed by Masahiko Sato who incorporated numerous cues from Nobuo Uematsu's original soundtrack to Final Fantasy V. Two soundtracks were released in 1994 with the first volume arriving on the 21st of May and the second on the 21st of July. The soundtracks remain a rare commodity with no official digital release available to this day.
Final Fantasy: Legend of the Crystals is difficult to find today because Urban Vision lost the distribution license for the series and it has not been released in any other format such as Blu-ray. The series remains available only on VHS tapes and the boxed set released in 1998. The absence of a digital release has meant that the series has not been remastered or remade.