Time Stream
"What's going on here?" "Where am I?" "Are they all me?" "Why can't they see me?"
Azzy fired questions nonstop to his older self as he wasn't able to connect with the Reaper.
The Demigod Azrael opened his mouth after his younger self finished with the questions. "Okay, if you are done, then, let me explain what's going on, Azrael."
As Azzy nodded, his older self continued, "This is called Time Stream or Time Corridor, a place in the null dimension where the creation of this universe happened.
The doors you are seeing are the gateways to various timelines. The right ones are to the past and the left ones are to the future. I wouldn't recommend the left ones though. After all, there are stronger versions of you who will take care of it.
And it is not that they can't see you, but they just cannot see anyone. If you ever visit this place later, then, you won't see anyone too and will feel like you are alone.