Daemons feats in the Eye of Terror

Solar System Sized, Planet Busting Bloodthirster:

A planetary system loomed up. He slowed further and steered close to take a good look at it. Its sun was huge, except that it was not what he would normally think of as a sun. It was not spherical but a flat disc, in colour a brilliant shimmering green. There were at least twenty different planets, each a different colour- mauve, russet, lemon yellow, magenta- but they were not arranged as planets normally are. Instead of being roughly in the same plane, their orbits criss-crossed at all angles, linke the electrons of an atom, and sometimes more than one planet shared the same orbit.
Then something appeared which caused Calliden to sit stock-still with shock. A figure was flying through the system, and it was bigger than the planets themselves, bigger than the disc-shaped green sun. A vaguely humanoid figure but crimson-furred, with a ferociously fanged, dog-like head, eyes glaring like pits of blood from beneath jutting horns, the head topped by great angled horns plus a twisted unicorn horn jutting from the crown. The creature was flying by, flapping great membranous wings which put a dozen planets in shadow with each pass. It wore brief, ornately worked armour down to the waist, glinting red and black, close-fitting except at the shoulders whch were protected by raised and extravagently worked pieces. The curve-bladed battle-axe it carried in one hand, holding the haft loosely as it flew, was bronze-black and vaster than any weapon should be. A supernatural energy seemed to flow and crackle through the unbelievable apparition, making it more solid-seeming, more real, than any natural creature.
"What- what-"
Calliden stuttered until his mind found a rational explanation. "It's a hallucination. Can you see it, Kwyler?"
Though frightened, Kwyler was not quite as astonished as the navigator. "It is real," he said quietly, his mouth dry. "A daemon, one of rank too."
Now something happened which confused Calliden at first. The apparition seemed to be retreating. Too late, be realized that it in fact was approaching, but diminishing in size at the same time.
The daemon seemed angry. It flew alongside the Wandering Star, no more than twenty times the size of the spacecraft now, glancing at it sidelong with its smouldering eyes, wings beating majestically.
"How can it use those wings to fly in space?" Calliden queried hysterically.
"It flies on warp currents. Be careful. Don't do anything. Perhaps it will go away."
Calliden shrieked and pulled on the controls as the warp entity, in a sudden rage, swung round and lashed out with the battle-axe, itself larger than the starship. The Wandering Star jinked aside, narrowly missing being crushed by the blow, then sped off.
The daemon did not follow. The spaceship was too minute to be worth the bother, no more significant than a gnat. When last he looked Calliden saw the immense Chaos creature, system-sized again, taking his frustration out on one of the circling coloured worlds, batting it sidewise with the flat of the battle-axe, and sending the broken pieces hurtling into the disc-shaped sun.
For the very first time the navigator felt that now he truly understood what it was that the divine Emperor was striving to protect the human race from.
Briefly he wondered if the smashed planet had had a human population.
-Eye of Terror Page 96-97

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

The Rose Cluster, created by a Greater Daemon of Tzeentch:

Multiple multi-coloured suns fled past, some misshapen, some ring-shaped, some joined together in complicated patterns by filaments of light and fire, some surrounded by what looked like intricate decorations made of gold and silver and brass. There was no consistency; no two were identical. It was a storm-enwrapped minor universe in which the normal laws of physics did not count. The will and imagination of daemons counted for more.
"The Rose Cluster," Kwyler kept saying. "Took for the Rose Cluster."
Calliden found it, coming at him from the darkness and distance, and despite everything that had already happened, he gasped with wonder.
"Maynard!" he called. "Come and look at this!"
The trader staggered from the pallet where he had been lying and peered out blearily. His arms dropped limply. His jaw sagged.
The Rose Cluster was, as its name implied, a large cluster of stars. Typically these were globular and contained thousands, sometimes tens of thousands of stars. In that respect, the cluster was unremarkable.
Except that all the stars were an entrancing pink colour. And the entire cluster had the shape of a rose. It was all there, the curving petals, hundreds of light years across, picked out in sheets of stars and glowing gas - also pink - the petals foliated one within another, layered down to a softly blazing heart. Some mighty daemon with a sense of beauty had crafted this. Calliden powered the telescope, feeding its image to the view-screen. One of the stars forming the cluster appeared before them. It, too, was in the shape of a rose, its radiant plasma magically suspended to form identical layers of soft petals.
"Every single sun in there is the same," Kwyler told him. "And that's not all. Every one of the planets in there is shaped like a rose too. Thousands upon thousands of them."
- Eye of Terror Page 97