Any time a Cat attacks on your behalf, you can also pay three mana (1 colorless, one green, one white) to give it Trample and +X/+X for the rest of the turn
Up to this point, Gravestorm has only appeared once on an MTG card, and it was a rather mediocre one
This synergizes with her ability that mills you four cards when she is cast, providing more artifacts to dig out of the graveyard
This deck died down over time, especially when Mox Opal was originally banned (Mox Opal is back, but there are plenty of stronger combo options in Modern than Cheerios)
Furthermore, this marks a major return for Dark Confidant into the Standard format
If youre drowning in fetchlands and have a Ramunap Excavator or Crucible of Worlds, then Oracle of Mul Daya is for you