Viddasala is a qunari high ranking Ben-Hassrath member and the main antagonist of Dragon Age Inquisition: Trespasser DLC. She believes the Inquisition are pawns of Solas and that magic from him is too powerful to be used, she think the only solution for this is to conquer the South and purge it from magic and current leaders.
She's a high ranking member of Ben-Hassrath specializing in finding and studying magic in order to stop and destroy it. She also is in charge of conversors of foreigners and the reeducators of Qunari dissidents. She fantically hates magic and sees the Inquisitor as a threat beyond comprahending that must be destroyed. However she hypocritically uses magic mirrors to teleport her forces on Thedas and feeds her qunari mages with lyrium to make them more powerful living weapons.
Depending on player's choice she can command Hissrad to turn against the Inquisitor. She chases Solas and ends pertified by him.