From the comprehensive rules:
205.2a The card types are artifact, battle, conspiracy, creature, dungeon, enchantment, instant, land, phenomenon, plane, planeswalker, scheme, sorcery, tribal, and vanguard.
Of these, artifact, battle, creature, enchantment, land, and planeswalker will be in standard. It's exceedingly hard to sacrifice battles and planeswalkers, and enchantments are often difficult as well. Let's say you sacrifice an artifact, a land, and a creature (which seems reasonable), you're casting this for 2BRG. As a 5-drop, this card seems incredibly powerful, assuming the opponent doesn't have a [[Sheoldred, the Apocalypse]].
Is this better than ramping into Atraxa? Probably not, but it comes out much sooner and fits well in a sacrifice deck.
