Recently got back into collecting, what constitutes as a Master Deck?

For context, I am currently at 102/120 on Dex (the app!) for the pitch black set. Whilst I have some of the big boys remaining, I also have some cards that are only obtainable via a “Build and Battle” deck, namely: Normal variants of Miraidon, Spiritomb, Bastiodon, Silvally and Volatic Energy, plus the “what’s your favourite” variant of other cards as well. My question is, given that these are locked behind other decks which are more difficult to get your hands on and can’t be acquired via a normal booster, are these required for a master set or just grand master?