This episode shows a new facet of Wraith personality: individualism. Also, a personal drive to do more than kill, take revenge, and feed is revealed.
The Stargate Atlantis team converted a large number of Wraith into humans using a retrovirus they engineered.
An escapee from the colony returned to his hive ship. There, however - he found he was no longer welcome. Rather than celebrating his freedom and safe return, his fellow Wraith make him a second-class-citizen.
This so infuriates and frustrates him that he decides to return to the Atlantis team. The irony is that they are responsible for the position he is in with his own people.
Nice to see the Wraith, one anyway, behave as something more than a highly-evolved insect.