So having seen the promo video and some of the bizarre boosts the scream cards are receiving I've had a thought that these cards will remain boosted all year but the boosts will cycle round different stats owing to the the reference to "Shapeshifting".
My expectation is the cards will be released as per the promo image but each full moon the boosted stats will swap round which could be a gold mine for gambling investors.
At the moment Busquests boosts look really useful for the position with 90 pace and defending handy for a CDM but at the next full moon this could swap to shooting and physical being boosted which would be less desirable and less of an improvement over the normal card in respect of the physical meaning the price could drop.
Conversely the Ballotelli defending and dribbling 90 stats could become 90 pace and 90 shooting which would make his price jump up.
This is only a theory but I'd be quite interested in using these cards and taking the risk from time to time hoping the shapeshifting worked in my favour.