For a Purpose
The Taken have come to disrupt your communion with the Traveler. Defeat the Taken.
Savathûn has sent her Taken to stop you from reforging Hawkmoon and carrying out the Traveler's will. You must survive.
"It's a warning. It's everything. It's us, it's Crow, it's the Taken, it's our path. Guardian, the Traveler is talking about the future. About how the choices we make will impact Crow and whatever his role to come will be." —Ghost