Alma the Angel

Alma 29:1-2 "O that I were an angel, and could have the wish of mine heart...I would declare unto every soul, repentance and the plan of redemption"
Alma 45:18-19 "it came to pass that he was never heard of more; as to his death or burial we know not of. Behold, this we know, that he was a righteous man; and the saying went abroad in the church that he was taken up by the Spirit, or buried by the hand of the Lord, even as Moses"

While still in the flesh Alma desired to be an angel so that he could preach the gospel to every soul.  It appears that he was granted this desire once he had finished what he needed to as a telestial creature.  If Alma truly was translated then it must have been for a purpose, an angelic mission.  Joseph Smith said, "translated bodies are designed for future missions."  Since this was before the resurrection this role may have required him having a body or he may have simply proselyted much like John the Beloved.  I'm sure Alma was eternally grateful to the angel that came and called him to repentance and he must have felt indebted to return the favor.