"Reach the Sentinel" is an objective in The Sentinel in Battleborn
Walkthrough[edit]
Head to the East through the hallway to reach the main chamber again. This time, you will be able to get through the door that was blocking your way forward and stopping you from getting to the Sentinel itself. Drop off the ledge and turn to the North after you cross the stairs.
Turn to the North from there and use the Jump pads to start on your way to the Sentinel itself. This leads to a Checkpoint that lets you launch from there to the platform with the Old Sentinel itself on it.
The boss fight will began once any member of the party touches down on the platform with the Sentinel.