diabolicamente bedeutet auf Englisch

diabolically▼(In a diabolical manner)
adverb
[UK: ˌdaɪə.ˈbɒ.lɪk.l̩i] [US: ˌdaɪə.ˈbɒ.lɪk.l̩i]He was diabolically intelligent. = Lui era diabolicamente intelligente.

fiendishly▼(in a fiendish manner)
adverb
[UK: ˈfiːn.dɪ.ʃli] [US: ˈfiːn.dɪ.ʃli]