Then again we must also remember that in truth, the Lord Ruler did not actually defeat or should I say kill the deepness or the ruin. From what I gather, He really just held it at bay, Imprisoned it you could say. So we really have no idea what power it could wield, Yes the primary power in the Final Empire is Allomancy, But that power is wielded by humans. What they are facing now is something completely different. It is said in the book many time's that the Lord Ruler was a divine creature, But when Vin finally killed him, we learned that he was just a man fueled by the same power and as Vin and Sazed. What I am saying is that possibly the power the ruin wields is not allomancy, something else yet. From a story stand point, Vin has fought pretty much every power the world can throw at her, So where does she stand. Another book having her fight yet another allomantic power is not what I would write as an author. She is now facing the most powerful enemy in the land, one that even the Lord Ruler didn't truly kill, So it is very hard to say whether or not the ruin uses allomancy or not, I would assume that it does in some way, but to affect those that it can enslave. I believe it's true power is going to be something else, But I would assume it uses allomancy in some way or another, and I still believe that the Inquisitors are going to be its primary henchmen.