It particularly synergizes well with this decks commander, the Sliver Gravemother, as once she is around you can copy legendary slivers and not lose them to the legend rule
Thing is, this is not a common occurence in cube even before you consider that to play this you need to be black and white, which means that less black and white drafters should be at the table, and so with black and white being the main weenie colours you will find this to be rarely at its best
Add in disruption from Empoleon LV.X, Empoleon from Stormfront (#2), and Empoleon from Platinum and you have yourself a really balanced line
Its a bit of a debate how powerful this card will be its Tranquil Flower ability provides consistent healing every turn, although it can be negated by the always prevalent Path to the Peak card
That is why other decks fell short again and again