rot13(Gung zrnaf gurer'f n svir-fvk-frira gevcyr va E4P7, E5P7, naq E6P6, naq guhf n gjb-guerr-sbhe gevcyr va E5P8, E6P8, naq E7P6. Svanyyl, gung zrnaf E7P8 pnaabg or gjb, guerr, be sbhe, juvpu zrnaf vg'f fvk, juvpu erfbyirf gur gra fnaqjvpu fhz.)
Just putting it here because I admittedly lack the strength to finish your sudoku now that I'm at a second impasse :P