"He is me."
Translation:Anh ấy là tôi.
I love questions like this, and they are the hardest to answer. They really test my Vietnamese knowledge.
Both đó and ấy mean "that" or "there." They are interchangeable, but I believe đó is used to refer to someone who is not in viewed. There is a little notion of the unknown, somewhat distant, less certain, and less specific than ấy. So "Anh đó là tôi" should work here since obviously "he" is not there.