For a more general rules overview, here's a reminder of how to play Magic: The Gathering
Answer: because the design team told us so, loudly and repeatedly
Don Andres, the Renegade Don Andres, the Renegade really likes Stolen Goods, and the evergreen Threaten effects combine with sacrifice outlets to be absolutely devastating when you pull them off
Not only does this mean you have two creatures to sacrifice, the spirit also comes into play untapped and able to block, unlike almost every other card on this list
Classic Genius This is the big one
Protection from black and red gives protection from two of the more key removal colors, and when you consider a lot of the best removal spells in the format are Orzhov, not having pro-white isnt the end of the world