ok, so, here's a photoshopped version of the ideal world I'm trying to describe:
The point here is that I don't want to do an HTTP request, I want to call an entity action and capture the result, if any, in a variable. Keep in mind that I'm describing an ideal world, and I'm OK to alternative solutions that still uses a Controller (and not an HTTP Action, that's temporary and I want to move to a custom Controller), wait for a response from a service, capture it and use in the same flow, if possible.
So, more like services than entity-oriented controller.
I hope this is better explained now. Thanks!