what's Bruce Willis doing in the end?

Rating: 8/10 (21 April 2017)

I don't understand why he's there and the most important thing is that what does he say"Mr. glass' mean.
B.W is uncredit for David Dunn for Unbreakable(2000),i don't see any related clues,is there?
And it appears Mr. Shyamalan will bring us a trilogy.