The two first met during the Omnic Crisis. They became friends quickly and joined Overwatch together. After the crisis Jack was promoted to leader of Overwatch. A rift was created between the two since Gabriel was passed over for the opportunity. Intel was given to Jack telling him that a businessman named Antonio had attacked an Oslo facility.
Reaper | Gabriel Reyes/Soldier: 76 | Jack Morrison - Works | Archive of Our Own
Reaper x Soldier76
They are a popular ship due to their canon connection through Overwatch, although the ship itself is not canon. However, Overwatch was destroyed in an explosion and Jack was presumed dead. He became a vigilante and fights for justice, as seen in the animated short ' Hero '. Gabriel Reyes used to be the leader of Overwatch before becoming part of Blackwatch , Overwatch's covert black ops division. Eventually he led a rebellion against the main part of Overwatch, which led to the explosion that destroyed its headquarters.