>>17000402i dont know about this gen but all legendaries apart from cresselia, the eon duo and the regional trios are banned, that includes stuff like manaphy and shaymin, im not sure if they changed it this gen
although i think its basically that any cover legendaries or legendaries obtained from events aren't allowed
im not sure what the reasoning is for that but i think the logic is that any pokemon that can be obtained in the game without any external source (imported regis, for regigigas, events, importing manaphys egg etc) are legal, if you need something else to get them, a separate game, internet event etc, you cant use them
(for example i think soul dew is banned not for balancing purposes but because its only obtainable from an event) i wonder why they do that