  In December 2015 the black hole binary V404 Cyg underwent a secondary
outburst after the main June 2015 event. We monitored this re-brightening with
the INTEGRAL and Swift satellites, and in this paper we report the results of
the time-resolved spectral analysis of these data. The December outburst shared
similar characteristics with the June one. The well sampled INTEGRAL light
curve shows up to 10 Crab flares, which are separated by relatively weak
non-flaring emission phases when compared to the June outburst. The spectra are
well described by absorbed Comptonization models, with hard photon indices,
$\Gamma \lesssim 2$, and significant detections of a high-energy cut-off only
during the bright flares. This is in contrast to the June outburst, where the
Comptonization models gave electron temperatures mostly in the 30--50 keV
range, while some spectra were soft ($\Gamma \sim 2.5$) without signs of any
spectral cut-off. Similarly to the June outburst, we see clear sings of a
variable local absorber in the soft energy band covered by Swift/XRT and
INTEGRAL/JEM-X, which causes rapid spectral variations observed during the
flares. During one flare, both Swift and INTEGRAL captured V404 Cyg in a state
where the absorber was nearly Compton thick, $N_\textrm{H} \approx
10^{24}\,\textrm{cm}^{-2}$, and the broad band spectrum was similar to obscured
AGN spectra, as seen during the "plateaus" in the June outburst. We conclude
that the spectral behaviour of V404 Cyg during the December outburst was
analogous with the first few days of the June outburst, both having hard X-ray
flares that were intermittently influenced by obscuration due to nearly
Compton-thick outflows launched from the accretion disc.
