Suppose a Targ player with Crown of Maureen is playing a Martell player with Sun Stroke (awesome card, BTW).
The Martell player puts sunstroke on a Targ character, Drogon for instance, who also happens to have Crown of Maureen. If Drogon attacks, and Martell chooses unopposed, could Drogon take control of Sun Stroke and attach it to a Martell player? Would Drogon still be dead, since he was Moribound at the time of moving the attachment?
Also, assuming the attachment can be moved to a Martell character, would the effect reverse itself, so if the Martell player loses a challange by 4 or more strength they will now be losing their own dude?