Similarly, if The Soul Stone is already harnessed and becomes a copy of something else, it stays harnessed, though it's very likely that won't be relevant until that copy effect ends
Kefka, Court Mage (Borderless) (Surge Foil) Printing Foil Condition Near Mint (NM) Rarity Mythic Rare Number 543 Market Price $114.46 Despite being one of the better new cards to build a commander deck around, Kefka, Court Mage is surprisingly less valuable than many other lesser cards
The First Sliver Last but not least on our list, The First Sliver gives all your other slivers Cascade
For a more aggressive approach to diplomacy, try having Shuri, the Black Panther helm the deck
Note that this can copy any spell that comes in mid-combat, and it even spots you extra mana with firebending