We present a detailed exploration of the most optically-luminous Little Red Dot (LHα=10⁴⁴erg/s, LV=10⁴⁵erg/s, F444W=22AB) found to date. Located in the Abell 2744 field, source A744-45924 was observed by NIRSpec/PRISM with ultradeep spectroscopy reaching SNR~100pix⁻¹, high-resolution 3-4 micron NIRCam/Grism spectroscopy, and NIRCam Medium Band imaging. The NIRCam spectra reveal high rest-frame EW WHα,0,broad>800Å, broad Hα emission (FWHM~4500 km/s), on top of narrow, complex absorption. NIRSpec data show exceptionally strong rest-frame UV to NIR Fe II emission (WFeII-UV,0~340Å), N IV]λλ1483,1486 and N III]λ1750, and broad NIR O I λ8446 emission. The spectra unambiguously demonstrate a broad-line region associated with an inferred MBH~10⁹M☉ supermassive black hole embedded in dense gas, which might explain a non-detection in ultradeep Chandra X-ray data (>10× underluminous relative to broad LHα). Strong UV Nitrogen lines suggest supersolar N/O ratios due to rapid star formation or intense radiation near the AGN. The continuum shows a clear Balmer break at rest-frame 3650Å, which cannot be accounted for by an AGN power-law alone. A stellar population model produces an excellent fit with a reddened Balmer break and implying a massive (M*~8×10¹⁰M☉), old ~500 Myr, compact stellar core, among the densest stellar systems known (ρ~3×10⁶M☉/pc² for Re,opt=70±10 pc), and AGN emission with extreme intrinsic EW WHα,0≫1000Å. However, although high M* and MBH are supported by evidence of an overdensity containing 40 galaxies at z=4.41-4.51, deep high-resolution spectroscopy is required to confirm stellar absorption and rule out that dense gas around the AGN causes the Balmer break instead.