(Bits of spoilers for the original game and the remake are below; consider yourself warned)

Zet/Zed:
  Zet is the self-proclaimed Grim Reaper's Penpal. He's a demon swordsman who is easily recognizable due to his green hair, his sword named Doom Bringer, and his custom 'Z' armguard. Zet's main goal in life is to join the Quarter Knights, the group that is attempting to resurrect the evil Mother. He figures that the best way to do so is to defeat Rody/Rudy and his group; unfortunately, every time they battle, he is left humiliated and often unconscious. After Belselk is defeated, Zet is confident he'll finally get his chance to join... until Zeikfried brings in Boomerang and Lucied as replacements. Sadly, even as the Quarter Knights drastically drop in numbers, Zet is still left in the dark. After Zeikfried launches the Gate Generator and everyone is transported, Zet arrives in Saint Centour where he finds the only remaining inhabitant: a blind girl. They become good friends and he starts taking care of her. Later, when Rody and his group show up, he transforms into Monster Z and challenges them to protect what he loves. Upon his defeat, the group spares his life and (in Alter Code: F) can recruit him into their party! Most of his special attacks come with risks attached, but when they do strike their targets, they'll be sure to leave an impact.

Veteran voice actor Takehito Koyasu portrays Zet during battles in the Japanese version of Alter Code: F. Battle voices are not present in the overseas versions of the game.

Oops:
  Oops is the TFL approved fanlisting for Zet/Zed. It's been open since June 30, 2004, and is currently displaying version 2. The name comes from Zet's theme song of the same name from Wild ARMs; I find it quite befitting considering his comical entrances, his attempts to delay/trap the protagonists which backfire on him, and his overall personality in general.

Fanlistings:
  The easiest way to find out is to stop by TheFanlistings.org; plus you can find other FLs you may want to join.