Gravemind - Terminal, Toy, and Skull (Anger) - When you reach an outdoor area with boulders you use for cover and a large purple ledge running around the perimeter above you, head to the far side and look into the door that exits the area after having dealt with the enemies here. The next room should have the ramp leading down with the curved supports on the sides. This lets you know you’re in the right spot.
Now head back into the larger room with the boulders and hug the right-hand wall a short distance to find the terminal. Next jump up onto the nearby rocks right by the terminal and use them to get up to the purple ledge that circles the room. Once on the ledge, turn right and follow it all the way to the end. You'll cross over the top of the exit door when doing this. At the very end of this ledge you'll find a fuel rod Grunt, as well as both the toy and the skull. Check the video at 14:35
for all three of these.