  Active Galactic Nuclei (AGNs) hosting disk water megamasers are well known to
be obscured by large amounts of gas, likely due to the presence along the line
of sight of an almost edge-on disky structure orbiting the supermassive black
hole. Correcting for the high obscuration is crucial to infer parameters
intrinsic to the source, like its luminosity. We present a broadband X-ray
spectral analysis of a water megamaser AGN in an early merger (NGC 5765B),
combining Chandra and NuSTAR data. NGC 5765B is highly Compton-thick and
reflection-dominated, following the general trend among disk megamasers.
Combining the exquisite black hole mass from masers with our X-ray
spectroscopy, the Eddington ratio of the megamaser is estimated to be in the
$2-14\%$ range, and its robustness is confirmed through SED fitting.
