What qualities do you think a person would need in order to be a good mediator

To be a good mediator you would be someone who is fair and understanding as these qualities are needed to end a conflict as the agreement needs to be acceptable to people on both sides. You would have to be hardworking and committed as if you are to end a conflict you have to take everything into account as well as having a understanding of what needs to be done which takes alot of time and is not an easy task. A good example of a mediator is john Hume who helped end the war between the IRA and British army in northern Ireland 

You have to be able to listen well. Be respectful. Consider both sides. Be patient.