KYMAVR may allude to "Khem-our" (black light), a form of Horus mentioned in H. P. Blavatsky's Secret Doctrine.
Sergei Grigor’evich was the great grandfather of Helena Pavlovna Fadeyeva-Dolgorukaya (H.P. Blavatsky’s grandmother and also the grandmother of Count Sergei Witte) and great-great-great-grandfather of Helena Petrovna Blavatsky.