The idea of "my skeleton isn't my own" is very new and creative to me. I got the "Activated" ending, and then the "Child Soldier". The concept was intriguing to say the least. We have no knowledge of our character except for the text choices and narration. Assuming Johann is an abusive friend or relative from the text was my first and final guess. What really creeped me was the constant "please come home". No other response, and further increasing my curiosity by having a large male figure with what looked like a large bracer and bandages around his head also saying the one line "please come home". The fact that she new about (if you choose it) the russian bullet caliber, the plastic bomb, and microchip was also confusing. However she could just be assuming. Either it's the art of video games changing the world and characters according to your action, or it's the narrator making up nonsense.
Rambling aside I think from a logical/realistic standpoint that our narrator is suffering from an abusive relationship with Johann and/or family, and due to this she has run away out of the country and stolen an Xray to investigate boogiemen. Afterwards due to Xray radiation and several incisions and even vomiting she makes up a story based on the chosen boogiemen.Honestly, I think that man was... Johann. Wrapped in bandages maybe after an accident. Maybe, after a cliche near-death experience he saw what he had done to this poor girl. And pursued her. Trying to get her to come home so he could make it up to her.
But I could be super f*ckin wrong ¯\_(ツ)_/¯