Up until the Omega quests, I had been operating under the assumption Venat's faction had formed after the Final Days were stopped in response to the whole issue of the third sacrifice to Zodiark, but now that it's been specified that it was before that, it just makes me wonder what the heck they were doing while the world burned.

Did they choose to simply keep their hands clean of the Zodiark business, or did they aid in finding that solution, knowing full well what it would eventually entail?

I don't think I'll ever really feel entirely at peace until we know precisely what details Venat did choose to disclose to her followers.