  In intermediate polars (IPs), the intrinsic thermal emissions from white
dwarfs (WDs) have typically been studied. Few reports have analyzed X-ray
reflections from WDs. We recently developed an elaborate IP-reflection spectral
model. Herein, we report the first application of a reflection model with an IP
thermal model to the spectra of the brightest typical IP V1223 Sagittarii
observed by the Suzaku and NuSTAR satellites. The model reasonably reproduces
the spectra within the range of 5-78 keV and estimates the WD mass as
0.92$\pm$0.02 $M_\odot$. The WD mass estimated by the proposed model is
consistent with that measured using an active galactic nuclei reflection model
and a partial covering absorption model. However, the choice of incorrect
parameter values, such as an unsuitable fitting energy band and an incorrect
metal abundance, was found to introduce systematic errors (e.g., $<\sim$ 0.2
$M_\odot$ in the WD mass) in the WD mass measurement. Our spin phase-resolved
analysis resulted in discoveries regarding the modulations of the equivalent
width of the fluorescent iron K$_{\alpha}$ line and the angle between the
post-shock accretion column and the line-of-sight (viewing angle). The viewing
angle anti-correlates approximately with the X-ray flux and has average and
semi-amplitude values of 55$^\circ$ and 7$^\circ$, respectively, which points
toward two WD spin axis angles from the line-of-sight of 55$^\circ$ and
7$^\circ$, respectively. Both estimated spin axis angles are different from the
reported system inclination of 24$^\circ$.
