Diabolical

[Hina Muqadas]

Pertaining to the devil; resembling, or appropriate, or
appropriate to, the devil; devilish; infernal; impious; atrocious;
nefarious; outrageously wicked; as, a diabolic or diabolical temper or
act.

[Sarah]

[devilish]

[PussyCat]

Characteristic of the Devil. Showing ingenuity or wickedness [on par] with that of Our [Dark Lord], [the Prince] of Lies, Satan. All hail him in his evil glory!

[Becky]

Cool, awesome, excellent, sick, [dope], tight, [rad], badass, [wicked].

[Tina]

[Literally] the best [way to] call someone [bad] as its one of the best words that also means bad

[Dave Paprocki]

The most [diabolical] person known to man is [rook] he is so diabolical he reinforces between [sights]