No. Although Amaimon features prominently throughout the series, there is no episode specifically around him.

The only demon king I know for sure is the earth kind Amaimon.

Amaimon's familiar, Behemoth, is killed in episode 17.

Not really, he just asked her the typical marriage vows you would say at the end of a wedding ceremony, and he made her nod yes through the chuchi-moth larvae/parasite he stuck in her neck. So... kinda-sorta? XD

The cast of Le bassin de J.W. - 1997 includes: Artur Albarran as TV journalist Cristina Alves as Rapariga da Vida Ludumila as Miuda Joana Azevedo as Catarina, Ariane Susana Bastos as Outros Anjos e Arcanjos, Raymon Diana Costa e Silva as Outros Anjos e Arcanjos, Oriens Manuela de Freitas as Puta Sofia de Sousa as Amaimon Graziella Delerm as Marianne Mariya Makhanko as Uriel Gracinda Nave as Outros Anjos e Arcanjos, Samael Hugues Quester as Jean de Dieu, Lucifer Tania Rosado as Outros Anjos e Arcanjos Ligia Soares as Outros Anjos e Arcanjos Sofia Sousa as Amaimon Vitalina Sousa as Outros Anjos e Arcanjos, Mezahel Anna Strindberg as Anja 3 Azarel Myriam Szabo as Bailarina Pipo Tartaglia as Violonista Cego Paulino Vieira as Cantor B. leza

Tetsuya Kakihara has: Played Ggio Vega in "Bleach" in 2004. Played Kisha in "Ginban Kaleidoscope" in 2005. Performed in "Rockman Zero 4" in 2005. Played Ronnie in "Black Lagoon" in 2006. Performed in "XXXHOLiC" in 2006. Played Additional Voices in "Seiken densetsu 4" in 2006. Played Green Tooth Johnny in "Black Lagoon" in 2006. Played Gang Member in "Black Lagoon" in 2006. Played Alvero Kronie in "Irisu no atorie: Guran fuantazumu" in 2006. Played Pharmacy Sales Assistant in "XXXHOLiC" in 2006. Played Mikoto Yutaka in "Purinsesu purinsesu" in 2006. Played Rico in "Black Lagoon" in 2006. Played Salaryman in "Hidamari Sketch" in 2007. Played Fujioka in "Minami-ke" in 2007. Played Taro in "Bekushiru: 2077 Nihon sakoku" in 2007. Played Simon in "Tengen toppa gurren lagann" in 2007. Played Haitatsu no Oni san in "Hidamari Sketch" in 2007. Played Mercutio in "Romio x Jurietto" in 2007. Played Townsman in "Kureimoa" in 2007. Played Jitensha Shonen no Koe in "Hidamari Sketch" in 2007. Played Bandit in "Kureimoa" in 2007. Played Caster in "Minami-ke" in 2007. Played Keiichiro in "Half-broken Music Box" in 2008. Played Kobun B in "H2O: Footprints in the Sand" in 2008. Played Fujioka in "Minami-ke: Okawari" in 2008. Played Meguru Akiba in "Kannagi: Crazy Shrine Maidens" in 2008. Played Jitensha Shonen no Koe in "Hidamari Sketch x 365" in 2008. Played Fujioka in "Minami-ke: Okaeri" in 2009. Played Natsu in "Fairy Tail" in 2009. Played Pegasus Tenma in "Saint Seiya: The Lost Canvas" in 2009. Played Cain Fury in "Hagane no renkinjutsushi" in 2009. Played Natsu Dragneel in "Fairy Tail" in 2009. Played Jin Kisaragi in "Blazblue: Continuum Shift" in 2010. Played Amaimon in "Ao no Ekusoshisuto" in 2011. Played Tom in "Toriko" in 2011. Played Gaul Galette Des Rois in "Doggu Deizu" in 2011. Performed in "Gekijouban Fairy Tail: Houou no Miko" in 2012. Played Sasuke Sarutobi in "Brave 10" in 2012. Played Ryuho in "Saint Seiya Omega" in 2012. Performed in "Warunorri the Movie" in 2013. Played Shino Inuzuka in "Hakkenden: Touhou Hakken Ibun" in 2013. Played Camio in "Makai Ouji: Devils and Realist" in 2013. Played Kisaragi, Jin in "BlazBlue: Alter Memory" in 2013. Played Keiichirou Tokugawa in "Fuun Ishin Dai Shogun" in 2014.