Reaper was not always known as the evil mercenary that he is today. He was originally known and born as Gabriel Reyes. He was born in Los Angeles. Before the Omnic incident occurred he was a soldier in the US army where he quickly rose up the ranks and later joined the organization known as Overwatch. He met officer John Morrison while serving in the army and they became close friends. Morrison and Reyes went on many mission in both the army and then later on in Overwatch when the incident known as the Omnic crisis was going on.
Due to all of John Morrison’s accomplishments during the Omnic war he was granted the highest position in all of Overwatch. Reyes saw this as a disrespect to himself and thought that he deserved the position. Reyes and Morrison no longer were friends after this and Reyes decided to go rogue. and destroy the Overwatch organization. He decided to travel all over the world and become a mercenary moving up the ranks in the underground world until he could have enough funds to start his own syndicate. Using all the funds he gained from being a mercenary he started hiring his own people and sought to destroy Overwatch single handedly. He went after the leaders like Winston, and other Overwatch members such as Tracer.
Overwatch Reaper would have been Reyes’ name if he had not turned evil. To this day nobody knows what Reaper’s true motives are and why he is doing all these things. They only know him as Reaper since his identity is still hidden by the clothing and the mask that he wears. Whenever he wants he could always turn back and join the side that fights for justice. The chemical explosion seems to have left his whole body mutilated, but in exchange he gained super powers. Using those new found powers which let him shift his form into a misty ghost like appearance almost nobody can challenge him head on in a fight. Few are capable of going head on with Reaper. Reyes likes to call his mission the Overwatch Reap.
Reaper in game is one of the only two true assassin play style of characters. Him and Genji both play like their perspective fantasy roles. They go from behind and flank entire teams to devastate them in short quick combo moves. Whenever you are fighting a Reaper you always have to make sure to move erratically because if throws his aim off significantly. Reaper can single handedly kill an entire enemy team with his ultimate Death Blossom. Death Blossom is one of the highest damage abilities in the game and it is an AOE ability that will deal damage to everyone around it. In Overwatch Reaper is a very mobile character that can move around using Shadow Step and can get to places to ambush the enemy from behind fairly quickly. He is not the most mobile character in a fight and does lose to other characters like Mei who will just end up freezing him and killing him after a certain amount of time.
Overall Reaper is a very easy character to learn but it is one of those hard to master cases. You can easily distinguish a good reaper from a bad one by the way the move and the way they play. His shotguns have a pretty big range so you can most of the time just point and shoot your way to victory when playing him. As long as you have steady aim and use Shadow Step and Wraith Form correctly then you can very well decide the outcome of the game for your team.