Pioneer managed to narrowly avoid a ban, with Inverter of Truth taking it instead, which synergised with Thoracle to achieve its win con
The only proxy allowed in sanctioned play is typically a judge-issued proxy for a narrow set of situations (like a card becoming damaged during the event)
Unlike Drannith Magistrate, who was deemed too oppressive by himself, Zirda, The Danwaker was banned for her joint powers derived from her artifact companion, Grim Monolith
For an Eldrazi Commander, the flavorful All is Dust is fantastic as it forces each opponent at the table to sacrifice all colored permanents they control, likely leaving the opponents with nothing but lands and colorless artifacts
Tormod is definitely the stronger of the two because black works better with the archetype and zombies have considerably more support that spirits, but you'll realistically play either one in your gravebreak deck, assuming your colors support them
Its another tool in the tool chest