  V392 Persei is a known dwarf nova (DN) that underwent a classical nova
eruption in 2018. Here we report ground-based optical, Swift UV and X-ray, and
Fermi-LAT \gamma-ray observations following the eruption for almost three
years. V392 Per is one of the fastest evolving novae yet observed, with a $t_2$
decline time of 2 days. Early spectra present evidence for multiple and
interacting mass ejections, with the associated shocks driving both the
\gamma-ray and early optical luminosity. V392 Per entered Sun-constraint within
days of eruption. Upon exit, the nova had evolved to the nebular phase, and we
saw the tail of the super-soft X-ray phase. Subsequent optical emission
captured the fading ejecta alongside a persistent narrow line emission spectrum
from the accretion disk. Ongoing hard X-ray emission is characteristic of a
standing accretion shock in an intermediate polar. Analysis of the optical data
reveals an orbital period of 3.230 \pm 0.003 days, but we see no evidence for a
white dwarf (WD) spin period. The optical and X-ray data suggest a high mass
WD, the pre-nova spectral energy distribution (SED) indicates an evolved donor,
and the post-nova SED points to a high mass accretion rate. Following eruption,
the system has remained in a nova-like high mass transfer state, rather than
returning to the pre-nova DN low mass transfer configuration. We suggest that
this high state is driven by irradiation of the donor by the nova eruption. In
many ways, V392 Per shows similarity to the well-studied nova and DN GK Persei.
