Welcome To The Impregnable Demon King Castle ~The Black Mage Who Got Kicked Out Of The Hero Party Due To His Unnecessary Debuffs Gets Welcomed By The Top Brass Of The Demon King's Army~Nankoufuraku no Maou-jou e Youkoso ~ Debuff wa Fuyou to Yuusha Party wo Oidasareta Kuro Madoushi, Maou-gun no Saikou Kanbu ni Mukaerareru ~ ; Welcome to the Impregnable Castle of the Demon King: The Black Mage Who Got Kicked out of the Hero's Party Due to His Unnecessary Debuffs Gets Welcomed by the Top Brass of the Demon King's Army ; 難攻不落の魔王城へようこそ ~デバフは不要と勇者パーティーを追い出された黒魔導士、魔王軍の最高幹部に迎えられる~