Thanks! It was quite surprising when it spawned, during the first 1/2 hour of the water event. My friend caught the same mon but his was not shiny.
For the move set, I don't know if there was any technical basis for it, but I evolved a string of fodder mon until I got 3 poor moveset in a row, then evolve the shiny. And it happened to be the double-dragon moveset.
(By the way, how does one become a Founding Member?)