B'Elanna Torres encountered him on the Barge of the Dead during a near death experience. Kortar called her a "mongrelchild" and recalled all the times she almost got onto the Barge of the Dead before. When her mother Miral appears on the barge, he told Torres that her dishonor had condemned her mother.
Kortar encountered Torres again after she had The Doctor induce another near death experience in order to save her mother. She offered to take her mother's dishonor onto herself but Kortar knew of the plan to reawaken her. After Torres stated that she would die, Kortar sent her mother to Sto-vo-kor and took Torres to Gre'thor. (VOY: "Barge of the Dead")
The script described Kortar as wearing "an ancient seafaring outfit" and being an "imposing figure" and "Captain of the Barge of the Dead". Later when he is introduced to B'Elanna, he was described as being "larger than life, a mythic figure worth of Klingon legend. The epitome of a warrior. But the anger in his eyes is edged with sadness."
This character was only mentioned in dialogue.
According to deleted lines from "Barge of the Dead", which fleshed out the legend of Kortar more fully, her name was Shelka. According to B'Elanna Torres, "I remember the myth of Kortar and Shelka. The very first Klingons. Their love for each other was so strong they destroyed the gods who create them." Kortar continued the story, "As punishment I was condemned to ferry the damned souls of the dishonored to Gre'thor. And Shelka..." then continued B'Elanna, "Cursed to walk the living world forever. 'And the two Klingon hearts would never meet again. Forever separated by that which distinguishes life from death.' It was my favorite fairy tale."