Merciless: This type of person lacks compassion and does whatever they believe needs to be done without regard to the consequences or other people's feelings. In the workplace, they often are the ones who have to do the difficult jobs that many other people hate to do, or just can't bring themself to do. They seem tough and untouchable, sometimes distant and unforgiving of anyone who they consider a problem or the "enemy". They are not afraid to say and do whatever they believe is the correct and proper thing and "political correctness" is probably not in their vocabulary.
Compassionate: This individual will be very warm and caring and will always be looking out for the best interests of others. They want to assure fairness and are sympathetic to the needs, problems and issues of others, especially if they believe the others are being treated unfairly. They will be the type to empathize with other people, forgiving them for whatever they may have done to cause a problem and will always be very kind and considerate in their approach to dealing with other people.