Ok, here's the thing about raping physics and gravity and all that: it doesn't have to be filled up. The principle of a dyson sphere is that you can build things larger than suns, and they don't implode because they're hollow. If you did have something like this, here's how it'd work:>Thermonuclear fusion core
It's mega-hot in the middle and it consumes things and burns the crap out of them to make energy>Photosynthetic mini-dyson-sphere
Around the thermonuclear bit is a big orb that's like a plant, and absorbs the vast amounts of heat and light that come out of the core>Huge hollow around the sphere
To deal with the crushing gravity in its center, it'll have to have some lattice that moves energy out to the outer body, which is far enough away to survive. Of course, this means that a plucky adventurer that can pierce the side can cut that shit open and cause it to implode when the core floats into the edge>Solar Sail Wings
To keep it moving, it'll have to apply the concepts of the solar sail, maybe with some windsurfing, and gravitational bouncing. Basically, light is made of photons, which have a tiny mass, and a big enough wall that gets hit by all of them gets pushed back. So, huge wings to move away from suns, gravity to move towards things.>Mostly pointless Brain - decentralised consciousness
This thing doesn't have predators, and it doesn't need to be smart. Mostly, it'll move towards small planets and away from suns, while it grows.It
's big enough that responses will take seconds to cross it, and it doesn't really need to be smart, so it'll probably stick to just having auto-responses based on light level. Auxin or some shit.>Super-hard body
Nuff said. The outside, the lattices around the inner dyson sphere, all that'll need to be really tough to survive in space. Heat won't be such a concern because it'll be producing so much from the middle.