Ruth•less
Adjective
Having or showing no pity or compassion for others.
"A ruthless manipulator"
Synonyms: merciless, pitiless, cruel, heartless, hard-hearted, cold-hearted, cold blooded, harsh, callous, unmerciful, unforgiving, uncaring, unsympathetic, uncharitable, remorseless, unbending, inflexible, implacable; brutal, inhuman, barbarous, barbaric, savage, sadistic.
"Ruthless killers"
"Harry you are completely ruthless." I whisper.
"I hate you!!" I scream in anger. I hate him, and I've never felt so much hatred for another being.