No need to mail Damon, it's in the rulebook since Day 1.
From the rulebook, p. 14:
Control and Ownership
Players “own” all cards that they brought to the game in their deck.
At the end of the game, all cards are returned to their owners.
When a card comes into play, it does so under the control of its
owner, unless otherwise specified by the effect bringing the card
into play. Some effects also allow a player to take control of an opponent’s
When an effect refers to “your” card(s) or an “opponent’s” cards,
it is always making reference to the current controller of the card,
unless a reference to the owner of the card is specifically made.
When a card leaves play (is moved to a player’s hand, deck, or discard
pile), it is sent to the appropriate out of play area of its owner.