After playing a ?Crystal Dragon? in a previous turn, my opponent magda’s rosed it; gaining control of it
In a subsequent turn, i used an eredon’s drum and the dragon my opponent controlled was buffed.
If this is an intended effect, then i also think the wording of the card should be changed.
Is the dragon still mine if i don’t control it?
Magic the gathering has cards that distinguish between control and ownership (see brand from urza’s saga) so that even if you lose control of a card, you still own the card.
Perhaps something similar should be accomodated for in order for the card text to be clearer.
Eredon’s Drum, for instance, could read “Give all creatures from your deck +2/+2 wherever they are.”
Even a creature rose’d by the opponent would have come from your deck so it would make sense.