The problem with the foreign advisor is that it is too generous to one specific opponent. In a four player game there will be players who lose because the player on their right has not given them all these foreign advisor benefits that have been given to other players. Tribute, masquerade, and possession are based on seating order but at face value their effect is neutral on each players deck. All can be played in ways that are not neutral though.
You could perhaps amend the foreign advisor by having a marker that starts in front of the first player to buy the foreign advisor. The player with the marker gets the "player to the left" benefit and then the marker is moved to the left. However, when a foreign advisor is played and the current player has the marker, the counter is moved once to the left before the card is resolved. The marker would not be needed in a two player game.