There have been so many variants of the clone effect since the original Clone in Limited Edition Alpha, whether it's got flash like Stunt Double, shifts power and toughness like Gigantoplasm, makes it an illusion like Phantasmal Image, allows it to copy planeswalkers like Spark Double, or many others
With a fantastic second attack that can easily be incorporated into preexisting Psychic-type decks, any competitive battler in TCG Pocket will no doubt want to use it once the set releases
Prize-splitting can be allowed under specific circumstances
In fact, any of the following original Wizards of the Coasts sets make a great starting point: *All links in the bullet points below point to eBay* Are Newer Pokemon Cards Worth Collecting
Even after digivolving, the Digimon's DP is treated as 3000 until the end of the turn
For draft or sealed, Wilds of Eldraine is a fantastic starting point for new or returning players