  IRASF11119 is an ultra-luminous IR galaxy with post-merger morphology,
hosting a type-1 QSO at z=0.189. Its 2013 Suzaku spectrum shows a prominent
Ultra Fast Outflow (UFO) absorption feature (v_out~0.25c). In 2021, we obtained
the first XMM-Newton long look of the target, coordinated with a simultaneous
NuSTAR observation. The new high-quality data allow us to detect at P>99.8%
c.l. multiple absorption features associated with the known UFO. Furthermore,
an emission plus absorption feature at 1.1-1.3 keV reveals the presence of a
blueshifted P-Cygni profile in the soft band. We associate the hard band
features with blends of FeXXV and FeXXVI He$\alpha$-Ly$\alpha$ and
He$\beta$-Ly$\beta$ line pairs and infer a large column (N$_H$~$10^{24}$
cm$^{-2}$) of highly ionized (log$\xi$~5) gas outflowing at v_out=0.27c. The 1
keV feature can be associated with a blend of Fe and Ne transitions, produced
by a lower column (N$_H$~$10^{21}$ cm$^{-2}$) and ionization (log$\xi$~2.6) gas
component outflowing at the same speed. Using a radiative-transfer disk wind
model to fit the highly ionized UFO, we derive a large mass outflow rate,
comparable with the mass accretion rate (M$_{out}$=4.25 M$_{Sun}$/yr, ~1.6
M$_{acc}$), and kinetic energy and momentum flux among the highest reported in
the literature. We measure an extremely low high-energy cut-off (E$_c$~25 keV).
Several other cases in the literature suggest that a steep X-ray continuum may
be related to the formation of powerful winds. The lack of a significant
momentum boost between the nuclear UFO and the different phases of the
large-scale outflow, observed in IRASF11119 and in a growing number of sources
with powerful UFOs, can be explained by (i) a momentum-driven expansion, (ii)
an inefficient coupling of the UFO with the host ISM, or (iii) by repeated
energy-driven expansion episodes with low duty-cycle, that average out on long
time-scales.
