Daemon feat

Greater Daemons assume forms larger than entire star clusters, then shrink down and push planets around:

It is an advantage of being a greater daemon that the quality of size, the greatest of restrictions placed on merely physical beings, means nothing. Size is a property of matter only. The disparate pair, allies of convenience if events fell that way, flew through the Door, the narrow pass through which all this time the forces of Chaos had been trying to overcome the Materium. Spread before them was what, in comparison with the galaxy in its entirety, was but an antechamber. Still they could fly here, for the space of the warp and the space of the physical world overlaid one another here, like oil spreading and swirling on water, creating rainbow colours. This was what some mortals called the Eye of Terror, and for rainbow colours there was the suspension and warping of physical laws, making new types of worlds possible.
The two great daemons flew through entire star clusters which for the moment were smaller than they were. They adjusted their size, dwindling as they approached their destinations. Each selected a suitable planet from their respective domains. They moved those planets away from their warming suns — it did not matter, the planets did not freeze; instead their atmospheres were heated by friction as they moved through the ether-like warpspace-realspace overlap. They brought the planets close together and drew out from the surface of each a long tongue or causeway so that they met and welded together. Here, then, was the field of battle: a verdant bridge between two worlds, lit by a glowing sky, blasted by hot winds, crackling with incessant lightning.
And on each of these worlds the war hosts were already assembled. Officered by daemon princes, its leading standard bearing the Eye of Tzeentch, raising aloft every magical emblem, herded by Chaos champions, half the population of the world belonging to the Chi’khami’tzann Tsunoi, armed and trained, mutated into their war roles, proceeded forth on to the battle-bridge.
Officered by daemon princes, its leading standard bearing the crossed-bars emblem of Khorne, skull-filled banners dripping blood, herded by Chaos Champions, half the population of the world belonging to the Khak’akaoz’khyshk’akami, armed and trained, mutated or else mutilated into their battle roles, proceeded likewise.
Far above, seated on floating thrones of gold and silver, the greater daemons directed the game, relaying tactics to their captains.
- Eye of Terror Page 85