Random thought- This isn't meant to be a theory or anything but...
I am personally of the belief that The Immortal And The Restless holds no weight to the Fnaf lore, at all. Yes, I get Michael claims he relates to Clara or that it could be pointing to one of the Afton kids not being William's... Though, the latter was never expanded upon and I don't think will EVER be able to expand from where the series is now. And Michael relating to Clara could just be a one off thing, people relate to characters, it happens and sometimes doesn't fully mean anything.
But I find it funny that some people focus so hard on him relating to Clara, which could be possible he acts kind of like her in a way but we don't have much of a personality to confirm that, when.. He kinda gained similarities to Vlad too. I see people say Vlad is William and I do believe it could represent him in SOME way. However it's amusing that the theme of the show, which very old timey vampire-like in it's scoring- bring that old classic vampire charm to it(which makes sense of course), plays when Michael, post-scoop and flesh suit'd, looks into the mirror at the end of Sister Location. Michael, who could now be seen as a classic case of the undead, who also gets known for having the color purple like his father.
It's just interesting THAT music played, not a more creepy or eerie soundtrack made specifically for that end cutscene. Could be the irony and it's very possible it holds no deeper meaning like how I imagine the show holds no deeper meaning, however it does feel like it's linking Michael more towards Vlad overall.
Like I said, I really don't think this means anything. If anything, it's funny to think about...
But if I did have to put on my tinfoil hat and dig into strange details that doesn't need to be looked at any deeper.
If I had to say The Immortal And The Restless represented anything, it would be one of three things.
1: Clara is mature, selfless, Michael talking back to Vlad, his younger and more selfish teenage self. The "baby" Michael is denying isn't a baby he had, it's a brother he had. He didn't want to truly see Crying Child as his brother at the time but after the bite, and after teen Michael "died", he sees him as a brother he wants back and wanted his past self to take care of, to be there for. And it makes it known that he couldn't change the past, he can't go back and rewrite the story because it's all said and done, proven by the fact that Clara and Vlad "making up" happens in the FAKE ENDING of the game. They never made up, teen Michael was never there for his brother.
2: Going off the theory that Michael once shared William's viewpoint and motivations in some way, even if in a tricked or naive way. Vlad represents both William and teen Michael's mindsets while Clara represents Henry and mature Michael's mindsets. And as stated before, Vlad and Clara's resolution(which was already iffy by itself considering Vlad never took accountability) was in the FAKE ENDING, so both sides never came to an agreement.
3: Vlad represents Ennard in Michael's body since the theme does play specifically while Ennard is wearing Michael's body as a skinsuit... But I literally have no idea what that would represent if that's the case. So I'm... Just leaving it at that.
Or it could be all three, who knows.
In the end, even if it has some meaning, I don't think it matters that much. We're too far along for it to matter unless we get another Fnaf game set in the past where we get more info on the Afton family but I doubt it.
This is just a thought I had and decided to share.