Who is Bogachevsky (Father Evlissi) from Meetings with Remarkable Men and what is their importance?

Bogachevsky is one of Gurdjieff's other teachers while he studies under Dean Borsh. Gurdjieff gives Bogachevsky credit for exposing him to the idea of spirits. Still grieving the recent death of a sister, Gurdjieff wants to believe that spirits exist. Dean Borsh tells the boy that if spirits can communicate to the living, they would do it in ways other than simply bumping the leg of a table. While thinking about Bogachevsky, Gurdjieff relates two stories related to psychic phenomena, one a reading from the half-wit man Eoung-Ashokh Mardiross and another about a young soldier who had apparently been buried alive.