One Step Ahead of You

Description: Kill the Opha before her spawned Putti activate the shielded door.

This challenge is performed towards the beginning of the Eleseer map, and can only be completed during the main story playthrough during the mission "The Beginning of the End" with the objective "Find the Vault Entrerance". At the beginning of the map, you must kill an Opha before Putti activate the three Onager turrets above the door leading towards the center area. It may be possible to lure the Opha away from the door and attack it from a position closer to the Fast Travel Station. However, a good way to attempt completing the challenge is by sniping an Opha from the eastern ledge where the single Cult of the Vault symbol is located as Putti fly to you in a direction away from the door.