Btw, the Man in Black his name is Samuel. Richard crashed on the Black Rock and was a slave on the ship. The first man to greet him was Samuel and Samuel didn't seem excited to see him, eventually Richard met Jacob and Jacob blessed him with the power of immortality and Richard has been around ever since trying to find someone "special" which you will find out what that means in Season 6.
P.S. Watch out the man in black can assume forms of other beings. (The Black Horse Kate sees, the Black Spider that paralyzes Nikki and Paolo. Etc. keep your eyes out.)