Complex sentence: The VTB United League Top Player is an annual VTB United League award given to one player from each country represented by the League's clubs, handed out since the 2012--13 season, it is awarded by citizenship regardless of the player's club's location.
Split into simpler sentences: The VTB United League Top Player is an annual VTB United League award that is given to one player from each country that is represented by the league's clubs. The award has been handed out since the 2012--13 season, and it is awarded by the player's citizenship, regardless of the player's club's location.