I'm getting into trouble here now that I'm debugging a test case.
readFrom takes Class<Object>, not Class<?>. I don't see how the JAXB code could work, as it will try to obtain a type for 'Object.class', which is the only thing in the world of type Class<Object>, AFAIK. My code certainly won't work. I note that none of your unit tests ever call the JAXB Element readFrom. I'll look for the systest. Aegis needs some clue about what types are going to be read.
