Same C'tan from World Engine

"Rising above the Necron army was a giant cruciform figure of pure light, the remnants of its energy cage still crackling around it. It roared in exultation at its newfound freedom, the booming sound throwing Ultramarines and Necrons alike to the icy ground. Louder and louder it grew, until the planet’s crust began to crack beneath it. As the being’s shout struck the surface’s resonant frequency, cracks became fissures and fissures became chasms, hurling hundreds of stunned Necrons to an icy doom. Tigurius mind-pulsed a warning to Calgar – this being was a manifestation of the star god Yggra’nya, the Moulder of Worlds, whose very thoughts could break apart a planet and reshape it in a form more pleasing to him."