Back in the day there was a strange post in the glitchcity forum, claiming that a unobtainable Shadow Loudred briefly appears during the purification demo.
It took us a year but we finally got in our hands. Other shadow entries (presumably from the same Purification Demo) has also been included.
These files are the 2 starters you got from XD Demo, the 3 shadow pokemon you snatch and a random Zubat from the first trainer.
Not that you can shinyhunt the starters (ID/SID/IV random but Nature fixed).
The demo can be found on the Multiboot Demo Disc of October 2005.
Like XD Colosseum had a demo which you can find in May 2004 demo disc, unlike it there is nothing really interesting to get, but hey that's always a demo we can get in hand ...
The files contain the 2 starters (Umbreon/Espeon) and 2 trainers Pokemon.
Thanks @BlackShark for dumping them.