Is the phrase "more and more x the more y" idiomatic? I think it is, but it's hard for me to know if it's the case and if there are some constraint to the phrase and how we can use it.
For example:
He became more and more angry the more the audience ignored him.
The vampire became more and more powerful the more blood he drank from his victims.
The legend became more and more widespread the more time went on.