Huh? has there been some sort of copy/paste mess up?
Not sure the Quadrant idea is such a good thing.
I'm trying to remember deatails about the Abyss from the book. Would you say it was as big/powerfull as the 'Planet Killer'? That would be the obvious basis for comparison rules-wise.
That or perhaps a massive battlebarge, I imagine bombardment guns/cannon would suit.