Before the invasion, Nicolas was very much the public face of Enweil and known to be a Blood Cult Elder. So it was was pretty easy for the anti-Enweil forces and the anti-Blood Cult forces to link the two together in order to gain support for their respective objectives.
From an outsiders perspective, I saw the BC as an influential, but not dominant, faction within Enweil's government. Generally what benefitted one benefitted the other.
