Discussion of the ending (Spoilers) (The Beast Inside)

From the very beginning strongly suspect that the name of the game is directly related to the plot) That is so here is a mini-spoiler before the game. But in any case the plot was very fascinating and intriguing, that play is a rarity. But something haunts me. So, Alex is more or less clear. He flipped on his work (or can work that did not exist and he invented everything?). But as its history is connected with Nicholas? Yes, they are relatives and Nicholas also suffered from a split personality. But what they still have the connection? What is told in parallel story from the past? Something like a hint of insanity in their family? And how Emma couldn't see her attacker in spy Alex? I understand he acted without a mask. And how your voice has changed?