I am currently working on a project. I took interviews of 10 people so far and created one user persona based on those ten people. Now question is, how many empathy maps am I allow to create? do I need to build empathy map each individual?
This is quite a question which I believe has no fixed answers. Research always depends on the context.
Short Answer: If you have multiple personas, there should be an empathy map for each.
Long Answer: At first, you need to clarify with yourself and the team that why you all need Empathy Map. Or do you need an Affinity Map instead? Do you really need those maps since you have Persona? Answering these questions gets you to the ultimate focus to the bridge between user's needs & business goals.
I think, there are some good resources there which are quite an excellent place to start about the need of these research methods and how to do it. So, by not expanding my answer, I'd love to provide those articles to you.