  We present deep XMM-Newton, Karl Jansky Very Large Array, and upgraded Giant
Metrewave Radio Telescope observations of Abell 746, a cluster that hosts a
plethora of diffuse emission sources that provide evidence for the acceleration
of relativistic particles. Our new XMM-Newton images reveal a complex
morphology of the thermal gas with several substructures. We observe an
asymmetric temperature distribution across the cluster: the southern regions
exhibit higher temperatures, reaching ~9 keV, while the northern regions have
lower temperatures (below 4 keV), likely due to a complex merger. We find
evidence of four surface brightness edges, of which three are merger-driven
shock fronts. Combining our new data with the published LOw-Frequency ARray
observations has unveiled the nature of diffuse sources in this system. The
bright northwest relic shows thin filaments and high degree of polarization
with aligned magnetic field vectors. We detect a density jump, aligned with the
fainter relic to the north. To the south, we detect high-temperature regions,
consistent with shock-heated regions and density jump coincident with the
northern tip of the southern radio structure. Its integrated spectrum shows a
high-frequency steepening. Lastly, we find that the cluster hosts large-scale
radio halo emission. The comparison of the thermal and nonthermal emission
reveals an anticorrelation between the bright radio and X-ray features at the
center. Our findings suggest that Abell 746 is a complex system that involves
multiple mergers.
