[TheBlackHawk]

"In order to catch shiny pokemon you have to decrease it's hp to at least 25% of its maximum hp."

I threw a masterball at shiny-spiritomb and got that message. It was at 25% hp so it should have worked. 

I was able to still catch this since I was using palkias radiation to lower it's hp steadily, but if it had been a shiny manaphy for example things would have been dangerous(to either killing it or having it heal).

[CeFurkan]

it could be 25.01