Strange Brigade

This is story related and cannot be missed.

After teleporting to the Sanctuary of Bes, make your way up the stairs of the temple and a Stone Guardian will appear. To defeat it, shoot away it’s armor until a blue orb is revealed on its torso and back. Continue to shoot at this orb until the Stone Guardian is defeated. When that is done, enter the temple and hold to drain the blue crystal sticking out of the floor to open the door to the inner chamber. Walk through the now-open door to find the last piece of the shield guarded by four enemies. Dispatch the enemies to lower the spikes surrounding the shield piece. Hold to reassemble the shield and the achievement will unlock.