The simplest explanation, which avoids almost all logical and physical pitfalls, is that Orion realizes that there is no real world, that everything is ultimately just information. Like in the Matrix, only there "real" people from a "real" world were trapped in a virtual dream.
In Orion's world, everything is virtual. If you allow yourself to think that, anything is possible. Teleportation, miraculous healing, "magical" worlds that can interact with "non-magical" worlds, even the "impossible" journey between universes is possible.
Otherwise, you can throw any attempt at a logical explanation that includes, for example, a healing by Calyso, in the trash.