With 003-091-ursula-deceiver-of-all doubling songs and 002-089-prince-john-greediest-of-all really putting the hurt with every discard, Emerald Steel promises a lot of card advantage, especially with an unanswered 004-070-diablo-devoted-herald
It would be powerful enough just to cheat free creatures into play, but putting them in tapped and attacking makes this a lethal commander that overwhelms the table with just a few combat steps
Though it may not appear a powerhouse on its own, Fandaniel lends itself incredibly well to mono black synergies
Used at the right time, this can be a huge blow against an opponent who is strategically saving an action for maximum effect
If you exile your entire library without exiling a legendary nonland card with lesser mana value, you will randomize the exiled cards and they again become your library, ending the effect
Even without that level of nonsense, its hard to make a commander that so thoroughly cheats on mana costs fair