One of the ways to use an HC born after the PoD, an ATL Twin is a character who corresponds with an OTL person, but does not necessarily share their personality AND name. The idea behind an ATL Brother is that both people share the same essence, basic personality, and role, but may have a different name/early life and also may have different ideas. This is one of the more spiritual approaches.
Why would you do this?
- ATL Twins are dual-function. Because they're filling a broadly similar role, anybody who's reading can instantly figure out what that role is, and that the world's convergently evolving. Simultaneously, though, you can introduce different details, setting up for future developments.