by PandaEskimo
This is a game where "OP" is part of the game. It's fairly quick and all about crazy combo's and lucky rolls.To answer your question, I would assume the answer about tokens ON the Power Card would apply to the energy cubes. My reasoning is that all of the tokens / other bits are just representations of state. Whether one is a cardboard disc or a plastic cube makes little difference. No distinction seems to be made at any other point in the game.
I would say whatever is on the card transfers when it's purchased. Whatever is on other players (poison etc) stays as well.
I don't have much to back this up other than extrapolating from the other rules and the feeling of the game. It would seem like an arbitrary exception to have the energy state wiped when other states are not.