Safe House.

No Vampire can hide from the ghouls. They don't have Origin domains. But even origin gods who have Origin domains can never hide from them forever. Primogenitors, no matter how powerful will eventually fall to the ghouls once they have a lock on it. It is something that she has seen before. 

Imagine it if a thousand Ghouls have locked on to a single vampire. That is something sure to happen to a Primogenitor. Every Ghoul will target them above everything else. They might have fused with their heart of Carnage as Monarchs, but a thousand Ghouls have a way of grinding them down and killing them forever.