I'm sorry for being such a noob, but i also have this question. I unlocked Jace and Gideon for 50 crystals each. I know that tapping in the little box at the bottom corner right before a match begins will take me to the planeswalker screen. I swipe the screen to change planeswalker but the change never "saves." As soon as i hit the back arrow to get out of the planeswalker screen and go back to the match screen the little box on the bottom corner once again has Nissa as the planeswalker of choice. It seems i am not allowed to use anybody but Nissa. Is there something im missing here or is it a game bug? Do I have to defeat all of chapter 1 with Nissa first before i am allowed to go back and replay the chapter as another planeswalker?