ruthlessly

ferociously fiercely mercilessly relentlessly savagely viciously

atrociously barbarically barbarously brutishly callously demoniacally diabolically ferally hardheartedly heartlessly in cold blood inexorably inhumanely inhumanly meanly murderously pitilessly remorselessly something fierce something terrible unkindly unrelentingly

gently humanely kindly nicely

calculatedly callously coldheartedly coldly cruelly deliberately dispassionately heartlessly indifferently intentionally premeditatedly unemotionally unfeelingly with full intent

brutally viciously

indecently inhumanly wildly

cruelly dishonestly perfidiously unconscionably unethically viciously

vengefully

brutally cruelly maliciously resentfully spitefully venomously