I'm going to tell you a whole bunch of stuff today!
As you know you get the 1st masterball after you defet Cyrus in Team Galatic's base, you get the second one by going to Jubilife city's t.v. station, go to the lady standing behind a desk ( this is the lottery counter ) you know the IDno. of a pokemon she will draw an IDno. and if she says all 5 of the numbers correct in the correct order she will give you a masterball, but you'll be very lucky if you do!
How pokemon get experience from the day-care center:
Your pokemon you left at the day-care, for every step you take your pokemon in the day-care gets 1 exp. point each.
Darkrai ( event pokemon ):
You get it with an nitendo event and trough-out the event you will get something, after that go to any pokemart and talk to the guy in the green shirt and he'll give you the Membership card. After getting that item go to the house behind the pokemon center ( the house that was looked ), but with the Membership card you can open the door there will be a man saying some strang stuff, then you takr a rest in his bed, but when you wake up you'll br on Newmoon Island go in the path you will see a pokemon it's going to be Darkrai go up to it then you'll battle it ( it's on Lv.40 but it's still hard to catch.
Shaymin ( event pokemon ):
Go through an nintendo event then go to any pokemart and talk to the guy in the green shirt, he will give you oak's letter, it says " go to Rt.224 " i'm going to tell you how to get there go to victory road ( north ) the guy blocking that entrence there will be gone go through that path there'll be a girl you have to help her get out of the cave. When you get out keep going north till you see Prof. Oak standing next to a white rock talk to him he wants you to say what you give your thanks to write anything you want, after that a small thing will come up and after that glow or whatever this weird pokemon will apere fpllow it up the really long path that's called the Seabreak path. When you finally come to the end ( Flower pasrade ) you find that same pokemon, this pokemon is Shaymin ( It's on Lv.30, but hard to catch )