Leehalt Alcaste is a main antagonist of Wild Arms 3 during Chapter 2. He is one of the three Prophets that desire to reshape Filgaia in their own image. It comes to light during Chapter 3 that he actually knew Virginia's parents, having been in love with her mother, as well as having once been a former scientist and member of the Council of Seven alongside her father.
The English localization of the "Leehalt"'s name seems to be yet another example of the Wild Arms series' notorious history with mistranslation, as according to at least one other source, the character's name is actually meant to be Richard Alkahest.
Wild Arms 3 Bio
Leehalt leads the Prophets. He is well versed in lost technology, and he is a master at peculiar etymology that can boot up devices based on ancient technologies. He is a masterful strategist who plans events behind the scenes and does not appear in the front lines of battles.
Leehalt, alongside his future fellow Prophets Malik Bendict and Melody Vilente, Virginia Maxwell's father Werner, Elliot Enduro, Duran Bryant and Pete Inkapilia were the last Council of Seven, a group of talented scientists who dedicated their lives to revitilizing Filgaia. He had an immense hatred of Werner, mainly because Werner constantlly overshadowed him and Leehalt loved Ekatrina, but she did not return his feelings and instead married Werner and gave birth to Virginia. The Council's efforts eventually led to the creation of the Yggdrasill tower which intended to fully restore Filgaia to its beauty, but due to the interference of Beatrice there was a massive explosion and all of Filgaia's life energy became concentrated in the surrounding area.
Most of the council died, but Leehalt, Melody and Malik were able to come back and restore themselves. Melody herself states that while she gave herself a beautiful new body, Malik chose to look exactly as he did before while Leehalt was more concerned with power - thus his pale skin and eyes. Thus, the three survivors became the Prophets, determined to use the demon library Hyades to transform Filgaia into a world of Metal Demons. They seem to require Panakeia fluid to keep their forms intact. In the 10 years prior to the start of the game, they presumably kept a low profile rebuilding Yggdrasill whilst recruiting Janus Cascade and his lackeys to gather the Demon Masks so they could summon the Dark Spear. Janus did receive this demonic weapon and thus gained the power to transform into a demon, thus able to gather Guardian Energy from the shrines, eg Lunatic Garden, for the purpose of reviving the ancient demon lord Siegfried. For Chapter 2 of the game, the heroes fight the Prophets in numerous locations as well as Janus and Asgard, a golem they revived to serve them.
Finally. Virginia and team learn of Yggdrasill and travel through the Nidhogg Pass, at the end they fight Leehalt for the first time and win, despite his formidable counter moves. He places a curse on Virginia that prevents her from gaining any Vit. Leehalt learns the woman he once loved gave birth to his enemy. Later, the team enter Yggdrasill and defeat each of the Prophets and Janus. After the team leave the tower and return to Boot Hill, the Prophets, very weakened, see a download from Hyades is incoming but it seems too late...then Janus emerges. Siegfriend enters the scene, bests Janus and gives the Prophets a history lesson on the demons in the olden days. Then, with the demon masks Janus collected, he transforms them into their demonic forms. The Prophets emerge in front of the Drifters as they are leaving a shrine with Shane Carradine, pillar of the Baskar Colony and introduce them to Siegfried. The Drifters are shocked at their new forms and go around to numerous locations, including Fila Del Fia, eventually learning of the Teardrop, their search leading to a confrontation with Maya Shroedinger and her gang in the Caging Tower. However, Maya is captured and forced into giving the Prophets the location of the Teardrop which is in a room in the Ruins of Memory. Once the heroes find it, a chain of events leads to the Prophets acquiring the Teardrop and rediscovering Asgard who had been sealed away by Gallows in Infinitum prior to the Yggdrasill battle. Thanks to Alfred, the team is able to enter Cradle of the Metal Gods via the Dim Root Path, defeat Malik and Melody for good, reach the Deus Ex Machina and confront Leehalt one last time, flanked by clones of the fallen Prophets. Defeated, he tells the party the truth behind Jet Enduro - a 'Filgaia Sample' adopted by Elliot with no original memories and the ability to re-write the programming of the nanomachines. Jet, in retaliation, uses his ability to destroy Leehalt once and for all, putting an end to the Prophets and therefore the Council of Seven for good...but they still have Siegfried to go through.