So what exactly is the Dark Bramble? [spoilers]

I've finished the game, and I'm quite satisfied with the answers to most of the questions I had about the setting, except I never really seemed to either understand or find an expiation for the dark bramble.

Why is seemingly full of pocket dimensions, and why did it seem to combine with the vessel according to the logs there? Where did it come from before it destroyed the planet inhabiting it's current space?

My idea was that it was probably a normal bramble lifeform on a normal planet until the vessel crashed (or even warped into the center of the planet by accident) into it possibly causing inter dimensional weirdness when the warp core broke, causing the bramble to take on some weird properties that make it so deadly. Doesn't really explain how a part of it ended up on Hearth near before the start of the game though.

Any thoughts?