Android MVP with RxAndroid + Retrofit

Recently I started reading a lot about MVP and I want to get into practicing my projects with it.

However I am not able to correctly understand where should Rx + Retrofit code go? I think it should be in Model Layer via Interactors but still can someone share some light on this?

Also what happens with the RX callback? the onNext(), onCompleted() and onFailure() passes data back to Presenter or do we implement listeners and then pass it on to Presenter?

I also want to persist data (Realm/StorIO) when I get it in onNext(), So again pass it to another DataLayer or where should it Go?

Also should we decouple Rx callbacks further?

I am following this post http://ift.tt/1LRq5G3

and this seperate github repo from antonioleiva.com http://ift.tt/1mNdzxn