All this sacrificing means youll also probably want some Recursion, too, so consider adding cards like Black/Green cards that will help you get things back from your Graveyard such as Phyrexian Reclamation, Greenwarden of Murasa, Reclaim, Regrowth or Skeleton Shard
Now, this isnt what many people will expect to see up here, but its our list, so deal with it
I understand that you need to run four colors to pull this off, and Im not sure if Standard has either the manabase or the cantrips to try to move in on that approach, but Modern should easily have all the necessary tools available (not really considering it for Legacy as combo decks have a much higher bar to climb there, what with Tendrils of Agony and Show and Tell alive and kicking)
At its worst, you can use Nykthos to tap to for one colorless mana
Because they overlap with the other thin branches in the art but should be behind those branches in a 3D version, they need to be set back a bit and made into their own piece, which Ill cut later