Gavin Verhey doesnt call it a watch list, but its the closest thing we have for a watch list for bans in Commander
The One Ring and Lrien Revealed are intrinsically tied to their universes
Additionally, Kozilek's Command has shown up as a four-of in all of the Eldrazi Ramp decks, shooting the card up to the $10 range
Efficiency can be determined simply by the reward you receive at certain mana costs (Counterspell and Cancel do the same thing, but Counterspell costs less), the total payoff you receive from a single card (Hull Breach and Decimate are both good cards, but Decimate usually covers much more ground), or the payoff you receive in conjunction with other cards (Anointed Procession makes other token production cards completely absurd if unchecked, which is usually better than adding one more card that simply makes tokens like Spectral Procession in a token strategy)
This is typically a blue ability, with cards like Sleep and Assassin Gauntlet, though white gets in on the fun with Blinding Light, Bond of Discipline, and a few others
