Who is or what role does Messiah ben Joseph play in the last days? Thank you.
Messiah ben Joseph is part of the Jewish tradition. I will try to summarize it but if really want more details you would need to ask someone more expert in such matters.
To summarize Messiah ben Joseph (also written as Messiah ben Ephraim) means Messiah out of Joseph (Ephriam). He is seen as prelude to the arrival of Messiah ben David. Messiah ben David is regarded by Christians as being Christ because he is of King David’s line.
The Messiah ben Joseph is to lead the lost 10 tribes back to Israel. Conflicts and wars break out, during these wars the Messiah ben Joseph is killed. This puts Israel in a bad spot and it is the arrival of the Messiah ben David that puts an end to the wars and ushers in his kingdom.
In this tradition it is not hard to see many potential parallels to what we as LDS believe. But as to how much is true? Well I guess we will just have to wait and see.