The new EA Mythic format was successfully decoded ;) I uploaded all muls (including index files). Usage: just download required archive, unpack it to uo classic directory and enjoy ;) You can use UO Fiddler or Inside UO (with some restrictions to tiles above 0x3FFF range) and viewing client's arts, gumps, sounds and maps.
http://69.64.34.13/ruosi/7.0.25.7/Art.zip - art.mul and artidx.mul ~40MB
http://69.64.34.13/ruosi/7.0.25.7/Gumps.zip gumpart.mul and gumpidx.mul ~18MB
http://69.64.34.13/ruosi/7.0.25.7/Maps.zip map0(0x,1,1x,2,2x,3,4,5).mul ~76MB
http://69.64.34.13/ruosi/7.0.25.7/Sounds.zip sound.mul and soundidx.mul ~102MB
P.S. I removed converter from file archive because that converter version will not work with new format and i will not release new converter ;)