Wiktionary
compassionless
a. Without compassion; hardhearted.
Usage examples of "compassionless".
They simply exist, compassionless, indifferent to the suicidal urges of flitting bugs.
This man in front of me, with his single-minded, compulsive, compassionless drive to control, faded into the background noise.
At other times, the reaper was not part of the scene but seemed to be the viewpoint through which it was observed, as if Hatch was looking out through the eyes of another—eyes that beheld the world with all the compassionless, hungry, calculating practicality of a graveyard rat.