- If Crystal Wall is attached to Black Kyurem-EX, can anything raise its maximum HP beyond 300 (ike if it were somehow made Colorless and Aspertia City Gym is in play)?
- Crystal Wall essentially replaces Black Kyurem-EX's printed HP with 300, and anything to add or reduce HP would work accordingly.
Source:
Boundaries Crossed FAQ (2012-11-08), TPCi Rules Team (2012-11-08)