It is assumed, like all wizards, that Vitae was not this wizards true name, but was instead taken when he began his wizardly studies.
Vitae was killed by Mandrake, the Betrayer, at the fall of Good King Omund.
Behind the Scenes
In one of the alternative campaigns that Matt had planned for the streaming show, Vitae would not have perished with Omund. Vitae and Ajax's wizard Mortum would have dueled in the skies above Castle Omund, where Vitae would have been soundly defeated and driven mad. Vitae was to have retreated to the depths of Castle Omund, and constructed a megadungeon, which the player characters would have explored.