  We report spectroscopic identification of the host galaxies of 18
ultra-strong MgII systems (USMgII) at $0.6 \leq z \leq 0.8$. We created the
largest sample by merging these with 20 host galaxies from our previous survey
within $0.4 \leq z \leq 0.6$. Using this sample, we confirm that the measured
impact parameters ($\rm 6.3\leq D[kpc] \leq 120$ with a median of 19 kpc) are
much larger than expected, and the USMgII host galaxies do not follow the
canonical $\rm W_{2796}-D$ anti-correlation. We show that the presence and
significance of this anti-correlation may depend on the sample selection. The
$\rm W_{2796}-D$ anti-correlation seen for the general MgII absorbers show a
mild evolution at low $\rm W_{2796}$ end over the redshift range $0.4 \leq z
\leq 1.5$ with an increase of the impact parameters. Compared to the host
galaxies of normal MgII absorbers, USMgII host galaxies are brighter and more
massive for a given impact parameter. While the USMgII systems preferentially
pick star-forming galaxies, they exhibit slightly lower ongoing star-forming
rates compared to main sequence galaxies with the same stellar mass, suggesting
a transition from star-forming to quiescent states. For a limiting magnitude of
$m_r < 23.6$, at least $29\%$ of the USMgII host galaxies are isolated, and the
width of the MgII absorption in these cases may originate from gas flows
(infall/outflow) in isolated halos of massive star-forming but not starbursting
galaxies. We associate more than one galaxy with the absorber in $\ge 21\%$
cases where interactions may cause wide velocity spread.
