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://18.104.22.168/ruosi/22.214.171.124/Art.zip - art.mul and artidx.mul ~40MB
http://126.96.36.199/ruosi/188.8.131.52/Gumps.zip gumpart.mul and gumpidx.mul ~18MB
http://184.108.40.206/ruosi/220.127.116.11/Maps.zip map0(0x,1,1x,2,2x,3,4,5).mul ~76MB
http://18.104.22.168/ruosi/22.214.171.124/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 ;)