>>37236633In ultra sun I caught a shiny quagsire in an ultra wormhole, nothing too special but still cool, then when I went to the pokemon center I was told I had contracted pokerus. Now, I was going to the pokemon center between each ultra wormhole trip, meaning that I am 100% sure that the shiny quagsire was the pokemon that gave me pokerus.
Now, I don't remember how far into the wormhole I was or how many rings it had but the highest shiny odds for any ultra wormhole is 36%, which would bring the odds of a shiny pokreus pokemon all the way up to 0.001647974%