modified
ruthlessly, cruelly, callously, relentlessly, mercilessly, heartlessly, unfeelingly, harshly, grimly, viciously, meanly, inhumanly, inhumanely, brutishly, savagely, in a ruthless manner, in a cruel manner, in a heartless manner, hellishly, pitilessly, barbarously, remorselessly, unkindly, unrelentingly, wildly, inexorably, fiercely, atrociously, hard-heartedly, murderously, ferociously, diabolically, ferally, barbarically, demoniacally, in cold blood, animalistically.
Antonyms gently, kindly*, mercifully.
