Let’s say I have the minion M, of which shadowcaster gave me a 1/1 “copy”. I let Carnivorous Cube consume the “copy”. What will be the stats of the pair summoned upon death of the Cube? Those of M, or 1/1?
Upon death of the cube you will get 2 original copies of M, regardless of what the stats of M are when the cube consumed it (silenced, damaged, buff cards, etc).
Example 1: You copy a Bonemare as a 1/1. If you cube the 1/1 Bonemare when the Cube dies you will get 2 5/5 Bonemares on the board.
Example 2: You copy an Edwin Vancleef as a 1/1. But it gets buffed to a 5/5 in your turn. Next turn you attack a minion and it goes down to a 5/2. You cube him. The cube dies, you get 2 2/2 Edwin Vancleefs on the board.