Stefan Kisaevna was a Manticoran citizen native the planet Sphinx.
He was married to Irina Kisaevna, and was among the last native-born Sphinxians to be affected by the final wave of the Manticoran Plague. Doctor Scott MacDallan did his best to try and save him, but Stefan reacted particularly badly to the virus, and was eventually killed by his own immune system. (SK1)