After inheriting the name and his mother's last name, Yang, Joachim became Welt Yang, the second Herrscher of Reason. This is how Welt came to wield the power we can see and use in Honkai Star Rail.

Welt Yang is a playable character in Honkai Star Rail, but there is also a person with the same name in Honkai Impact 3rd. HoYoverse made both games, so it's only natural that there will be some ...