Don't take it too seriously. It is a Hollywood production i.e. a jewish production.
Yes they used the Demon name Valak aka Volac. Remember our gods were bound at the time this "happened". And they didn't even use the correct pronounciation due to our gods are free and jewwood would have had a bad time using the correct name. Even though, they still will be met with disaster in portraying demons as evil. And for all the other crap they do.
There are entities out there who are malevolent and nefarious. Those entities can portray themselves as anyone so to speak, if they are powerful enough.