If you cast a spell with demonstrate and both you and an opponent copy it, the opponent's copy will resolve first, then your copy will resolve, and finally the original spell will resolve
This fits into any Commander deck and gives a creature a massive pump, an evasive keyword, annihilator
Uurg, Spawn of Turg Uurg, Spawn of Turg now uses erratad surveil text on its first ability, but its an imminently fair card, given its restrictive mana value and the work you have to put in to make it a 2/5 or bigger
As I said at the start, all decks should have a plan for the graveyard in some form, regardless of the commander you choose to run
These 10 cards pay homage to the classic style of science-fantasy book covers