I've had some issues where the game freezes right after I get a level up, resetting the level up and taking up my use of that trainer. It de-optimizes the character and makes the game less fun than it could be.
The descriptive text for the ambrosia stone is incorrect. It claims that the player that destroys is gains 20 life. The actual rule is that when an ambrosia stone is destroyed the player opposing the side with that stone gains 20 life.