Pylon was actually N’Takki, a warrior caste member of the H’San Natall. N’Takki also assumed the role of Congressman aide, Garrison James. Using these false identities, N’Takki was able to completely discredit the Teen Titans. After revealing his true nature, N’Takki released a gas that killed all 3,500 members of the Veil.
The defeated Teen Titans were captured and brought to a H’San Natall ship for reprogramming, as Pylon revealed his true identity to the team. The H’San Natall’s invasion plan was accelerated, but then stalled as Prysm was reunited with her alien father and human mother. And eventually, the Titans – with the help of Superman - were able to talk the H’San Natall out of any further acts of aggression.