Magic Duels

The five Origins Planeswalker cards are "Kytheon, Hero of Akros", "Jace, Vryn’s Prodigy", "Liliana, Heretical Healer", "Chandra, Fire of Kaladesh" and "Nissa, Vastwood Seer". One for each color, and the only way to get them is by oppening Booster packs. 

Each Booster pack has 6 cards and it have a little chance of one of them been a Planeswalker (a mythic rare card). Doing Daily Challenges and winning Versus battles are the best way to get coins after you beat the campaign.