Adverbs for Fiendish

barbarously; coldly; stonily; diabolically; inhumanly; unnaturally; defiantly; ominously; ungovernably; uncontrollably; insatiably; unspeakably; inexpressibly; uncommonly; brutally; incomprehensibly; unthinkably; odiously; atrociously; heinously; flagrantly; outrageously; outlandishly; grotesquely; inscrutably.