Blood Fountain and Broodheart Engine are literal engines for your graveyard, and represent a large card advantage when you recur them
A little politics will surely come into play with this creature card
Anyway, the card is also just as important for Zombies as Champion of the Parish is for Humans, especially when you consider that where Humans uses Thalia's Lieutenant to double-dip on counters on turn two, Champion of the Perished can actually combo with Lazotep Reaver to do the same
The cards typically searched by Protean Hulk include [c]Karmic Guide[/c], [c]Kiki-Jiki[/c], [c]Mirror Breaker[/c], and [c]Carrion Feeder[/c], which could collectively one-shot the opponent by comboing together
The Swiss Army knife nature of Deathrite Shaman is appealing, as is its defensive body and the incidental graveyard hate it provides, but it was always the mana generation ability that pushed this card over the top