If you arent confident about whether or not a promo card in your deck is tournament legal, you can visit the page Pokmon TCG Promo Card Legality Status on Pokmons official website to see when new cards become legal and which promo cards are already legal.
Players who buy Collector Boosters enjoy them, and we have no plans to change anything about them (well, big picture, they're customized to fit the set they go with, so they do evolve over time)
It seems pretty great in Norman Osborn Goblin, the current flavor-of-the-month Commander deck, for example
williamcoolman September 4, 2017, 11:41pm 5 I opened up a Roaring Skies booster out of official product from the pokemon centre and got a M Rayquaza EX regular
He pursues a personal agenda of technological progress on his homeworld of Kamigawa, determined to make the plane a better place for himself and his family
you use a specific item