You're allowed to play as many Game Changers as you'd like (they're not banned cards), but the number of Game Changers in your deck determines which bracket your deck falls in
The card has only just started to increase in price again, and I wouldnt be surprised if it ends up in the $8-$9 range at some point.
Cards that are just quite good frequently don't make the cut in the aggressive decks as the few slots are reserved for cards you need to do a specific thing such as a Viridian Shaman
I didnt count on that having to compete with the popularity of a Ninja deck with Red in it
The first few options that sold me on this deck idea were the upgradability of creatures like Bearer of Silence, Sky Scourer, Dimensional Infiltrator, and Mist Intruder as resurrection targets for reasonably-sized fliers
With the release of Adventures in the Forgotten Realms , one card in particular from this set has caught my eye as a fantastic way to combine themes both in AFR and another recent standard set, and that card is the card that was given to celebrate Dungeons & Dragons 5e, the Dungeon Master