Whisk the condensed milk and water and a bowl. Whisk in the putting Mix for 2 minutes. Let stand for 2 minutes or until soft-set; fold in the whipped topping.
Arrange half of the cake in the bottom of a 14-cup trifle dish. Sprinkle evenly with a layer of blueberries. Spread half of the cream mixture over the blueberries and gently spread. Top with a layer of strawberries. Layer the remaining cake cubes on
top of the strawberries, then add more blueberries and top with remaining cream mixture. Finished with remarry strawberries and blueberries, arrange them in a pretty pattern. Cover and refrigerate at least one hour.