This isn't his Earth. He did everything to check and it isn't. This is some weird alternate universe version of Earth that never had pocket dimensions affecting its history.
No one is going to miss him. His immortality is going to produce a fork back and no one will know this Felix exists.
Because, despite how ridiculously over-engineered it is, his form of immortality can't create a connection between different universes. So when Felix was snatched by the weird energies in the Bermuda Conflux the result was one Felix landing on another universe where his immortality's magic activated a fail-safe. He cough up a floating rock, which will eventually grow into a boulder with a fountain o top.
Meanwhile, back in Felix's original universe the original boulder-with-a-fountain-on-top must have accounted Felix's body as destroyed and activated the process of creating a new body for the magical-backup mind. In a week that instance of Felix is going to raise out of the fountain fully formed and maybe just a bit confused by the incident. But completely unaware of what happened to this Felix.
(He should be glad that no one is going to suffer because of him.)
The connection between the immortal and the fountain is ridiculously strong, anything that represents a obstacle to it is going to be a ridiculous obstacle for physical travel.
In other words, (this) Felix is on his own, on a strange world where he can't even go out in the street without drawing attention and any means of going back look downright impossible. He still
However, none of that matters.
Because, there is another dreamshaper around. One that needs to be rescued from the magically induced sleep that one suffers when they first acquire dreamshaping.
Felix opens a portal to the new dimension.