There Will Be Blood ending explained

What happens

Years later, Daniel is rich and alone in his mansion when a desperate Eli comes begging for money. Daniel makes him denounce his own faith, then beats him to death with a bowling pin. He has won, and it has left him empty.

The last line

"I'm finished."

What it says

The ending is the film's argument made literal. Daniel destroys the last man who could match him, and finds nothing left to want. Winning everything was all he ever aimed for, and the film shows how little that leaves him.