via Eurogamer
Diablo 4 players have long wanted to bring their Eternal characters into the Seasonal realm, and now they're getting their wish, sort of
Blizzard is introducing a long asked-for feature in Diablo 4 in the game's next update, which is already on the Public Test Realm for testing. The feature is called Rebirth and it finally allows you to use characters from the Eternal realm for Seasonal content.