That's actually a good theory in my opinion . I thought of something similar but I know for sure it's going to be wrong. I was thinking that maybe he also played the game (highly doubt it though bc it's mostly girls who play games like that) and got frustrated just like the FL and felt bad for her for having bad endings. Similar to the FL, he was put in the game and saw everything they did to her leading to him hating all the MLs. Now that she managed to unlock the secret mode, he's now able to stop her from dying. Idk but I do wonder if he know the FL in the real world or just the FL in the game .
No cause that is also good
Okay, okay. What if he was kind of like not let to interact because of the system but had to watch the fl suffer until she completed the routes and that was when he could move. As it’s obvious that he will probably kill all the previous ml. Or maybe he is from her world! And knew her! And liked her! and decided to go into the game for herrrr (don’t mind me I am just crazy and delulu)