Sometimes there's nothing they can do. Sometimes by the time they figure out why they're around, the damage has been done. Fracture looks over the remains of Protean City. They sit on an overturned tree on a hill overlooking the area. The sky is broken, and wispy green light falls in droplets onto the earth.
They take out their camera and look at the devastation, but after a moment's reflection, they lower it with a sigh. Usually they're treated to horrible displays of destruction, monolithic beasts that ravage worlds or great explosions of titanic force. But every now and then, a dimension ends with quiet wind and distant thunder. This is one of those times. The wind tugs gently at their hair, not a howl so much as a sigh. It's peaceful this time.
But they stand, and lift the camera to the sky. They focus in on the rift and take a picture. As the image fades into existence on the polaroid, they tap their lip with their pen. A great cracking sound rings out, and the ground begins to shake. They have just enough time to write two words on the back of the picture: Memento Mori.