forgrim wrote: previously, you could only level a total of 50 levels of a card's power, as in 20 yellow, 20 red, and 10 blue. you probably have yellow and red maxed out so you can't train blue anymore. this was stated in a tutorial (i believe) and therefore isn't a bug. its to create the ability to choose what powers you want to max or a random mix of powers instead of just maxing all 3 to max.