To own (play as) a Rider you must first beat their misson when fighting them. This could be something simple like "Use a Item during the fight" or "Do 500 or more damage in one attack" But it could be something like 'Win using Counter" or "Win in 4 rounds or less.
Exactly. You need the QR code card that you can only get when you purchase either the waffer candy (that comes with 1 AR card + 1 QR code card) or when you get a AR card from the Gachapon machine (1 card + 1 QR code) If you don't actually purchase the product, then you can't play with the card that you scan =/