He sympathized with the plight of the Narn (Comes the Inquisitor), and when Londo assigned him as cultural attaché to Minbar (A Day in the Strife) mainly to keep him safe from the coming trouble, he used his position to traffic Narns to safety before it was taken from him - which, to his relief, also jeopardized his arranged marriage to Lindisty (Sic Transit Vir).
He was recalled to Centauri Prime by Londo to help him remove Emperor Cartagia from the throne - only to unwittingly end up doing the job himself (The Long Night). He still suffers terrible nightmares from the affair (No Surrender, No Retreat).
Londo appointed Vir as his successor as Ambassador to Babylon 5 upon Londo's ascendency to the Centauri throne (Meditations on the Abyss, The Fall of Centauri Prime). Involvement with a group of Techno-mage initiates led Vir to discover the Shadow Planet Killer that the Drakh used against the Alliance (The Long Night of Centauri Prime, Armies of Light and Dark (& A Call to Arms)). From here, Vir heads a resistance movement that he dubs the "Legions of Fire", dedicated to fighting against the Drakh influence on Centauri Prime, which eventually succeeds (Out of the Darkness).
Finally, as predicted by Lady Morella (Point of No Return), Vir also succeeded Londo as Emperor (War Without End, Part II, Sleeping in Light), taking Lord Refa's daughter, the Lady Senna, as his mate (Out of the Darkness).
Played by Stephen Furst, who directed several episodes of the series, and appeared in the movie The Dream Team, among others. He is also the author of a weight-loss book, Confessions of a Couch Potato.