In the movie Troy, what on Earth did Briseis see in Achilles?

We all know the Iliad version. But in the movie, Achilles invades her country, kills heaps of people (inc. Hector), s her even though she was holding a knife against his throat, beheads the golden statue of Apollo, ransacks her temple - killing all the priests too, and then helps to ault Troy, causing the city to be burnt. But in the end, Briseis forgives all of this and doesn't want to leave him. None of this seems to make sense...