I wrote up a nice little summary on this card a year ago after it was initially discovered by @mikejofthecoast–very cool that you found it on your own as well! I always just thought it was a bunch of falling rocks haha.
I think the part that ties it all together was that this card was the one and only card illustrated by Kunihiko Yuyuma…who just happens to be the Executive Director of the Pokemon anime in every saga from Indigo League through Sun & Moon!