A guy online had a Black Kyurem in a Cherish Ball; he also had a Palkia in one as well.
He had a full team of legendaries, is it possible, or is it hacked?
Black Kyurem could be hacked, it could not be. You could get Black Kyurem from an event, and it would be in a Cherish Ball. Palkia could be hacked, it could also not be hacked. You could get Palkia from an event, and it would be in a Cherish Ball. It could be possible for it to be legit, but they probably hacked them in. Source: https://bulbapedia.bulbagarden.net/wiki/Palkia_(Pokémon) and https://bulbapedia.bulbagarden.net/wiki/Kyurem_(Pokémon)