  The first paper in this series showed that QCD axion dark matter, as a
highly-correlated Bose fluid, contains extra-classical physics on cosmological
scales. The nature of the derived extra-classical physics is
exchange-correlation interactions induced by the constraints of symmetric
particle exchange and inter-axion correlations from self-gravitation. The paper
also showed that the impact of extra-classical physics on early structure
formation is marginal, as the exchange-correlation interaction is inherently
non-linear. This paper continues the study of axion structure formation into
the non-linear regime by now considering the case of full collapse and
virialization. The N-body method is chosen to solve the collapse problem, and
its algorithms are derived for a condensed Bose fluid. Simulations of isolated
gravitational collapse are performed for both Bose and cold dark matter fluids
using a prototype N-body code. Unique Bose structures are found to survive even
the most violent collapses. Bose post-collapse features include dynamical
changes to global structures, creation of new broad substructures, violations
of classical binding energy conditions, and new fine structures. Effective
models of the novel structures are constructed and possibilities for their
discovery are discussed.
