I'd use "summons" if it is for some vamp alter but make sure you separate the television show to how it got to you very quickly to be understood. That involves understanding what created it it's role and function for your system. I think that is why it is usually takes a while for dx's for some of us probably some normal alter not necessarily traumatic like some of the littles are. To be understood you have to use some of the lingo if not.

Invoke, summons, call for the alter, ask inside all terms commonly used. If you watched the television shows then you might want to ask inside are there extreme feelings or obsessesion as to why if no co consciousness? I think if you know how your system is structured the alter type that would be a great idea even if no co consciousness.