Partner (You can have two commanders if both have partner.) If your Commander deck has two commanders, you can only include cards whose own color identities are also found in your commanders' combined color identities
The Soul Stone (Cosmic Foil) Mythic Rare, 242 Its a bit odd that the rarest variant of The Soul Stone isnt serialized (that is, with a limited, numbered print run which is emblazoned on each individual copy of the card), when so many Universes Beyond sets have featured serialized cards
Your win con is probably using cards like Tezzeret, Master of the Bridge and such to lean into the life loss aspect, but you could do any number of wincons really
In these extremely rare cases, uncommon cards can be worth hundreds of dollars
Rares/Mythics : I treat these with extra care, organizing them alphabetically in a separate binder or box to maintain their condition
The battle card shows a fairly unique crystalline elemental as well, which, when added to the lore we get from the viashino on Karsus Depthguard, begins to give us an idea of what Karsus is all about
