  Bohr's complementarity principle has been challenged by quantum
delayed-choice experiments wherein quantum systems are claimed to behave
neither as wave nor as a particle, but in an intermediary way. However, this
conclusion has been supported by retro-inference and with no direct link with
the system quantum state. Here, we consider a framework that employs an
operational criterion of physical reality to diagnosis the system ontology
directly from the quantum state at each instant of time. We show that, in
disparity with previous proposals, our setup ensures a formal link between the
output visibility and elements of reality within the interferometer. An
experimental proof-of-principle is provided for a two-spin-1/2 system in an
interferometric setup implemented in a nuclear magnetic resonance platform. We
discuss how our results validate, to a great extent, Bohr's original
formulation of the complementarity principle and unveil morphing reality
states.
