As far as I know, it can't be done.
If explorers of time and explorers of sky are the same, I think you can't fight team Raider.
Fight Darkrai
get ready because soon you have to fight Palkia & Darkrai
The last Pokemon you fight is arceus in destiny tower. Destiny tower has 99 flors so it is hard. also you have to entr at lvl 1
go though a dungeon with cresslia and when you reach the end you will fight darkrai
fight him again
yes. But after you beet the game and fight darkrai it gets very boring. So, might Want To think of another game
Yes and in the very Begining you fight apart of team Skull Koffing and Stuncky.You fight Team Skull on the expitditon.
1 plus boss fight
Just head back through Aegis Cave and fight him again. There's a chance of recruiting him whenever you fight him.
10+ bottom ( groudon boss fight - about 600 hp)
If you are talking about Pokemon Mystery Dungeon Explorers of Sky then you cannot, but you can fight Mesprit once you save the world from paralysis.