血も涙もない (translations)→ flinty heartless mindless
非情な (translations)→ inexorable inhuman iron steely tough-minded
平気で (translations)→ blithely easily readily undeterred
無慈悲な (translations)→ coldly graceless heartlessness mean unkindly unmerciful
容赦ない (translations)→ merciless painful spare
ruthlessly
