Darksteel Pendant and Crystal Ball are not good enough in my opinion and are too much of a resource investment unless there is some sort of artifact strategy I am missing
Peculiar rules text and narrow interactions are potential reasons a player may omit an enchantment card from a Commander decklist
For more versatility and the ability to handle small batch cutting, pairing a Sizzix Big Shot with a custom steel rule die is an excellent flexible alternative
If we went such a route, we might also try Indulgent Aristocrat as an additional payoff
Force of Negation Force of Negation is discussed at length here, but the short version is that it looks like a very solid Negate variant that happens to be especially attractive for combating fast combo decks
Often overlooked, Liliana, Deaths Majesty helps the player to fill the graveyard with milled cards to put on the field later, and can quickly create zombies to control the battlefield