Indicative or subjunctive?

Question

Does this construction always require indicative or can it also be used with subjunctive?

Answer

Hola Felix
If you are referring to the actual expression using ser (not the verb used after "que"), yes, but not very often. The nature of the expression generally requires the indicative, but if you have an introductory sentence that triggers the subjunctive, you may find the subjunctive too. For example:

Dudo mucho que Victoria sea de un creído que ni te imaginas, como tú dices. A mí me parece una chica muy simpática. 
I doubt/don't believe that Victoria is so vain that it makes us all hate her, as you say. I think she is a very nice girl.

If you were referring to the use of the subjunctive after "que", for example:
Victoria es de un creído que haga que todas la odiemos
then, no, that wouldn't be correct. 
Saludos cordiales
Inma