Shadowmoor introduces new mechanics and a new card type
Zanarkand, Ancient Metropolis is the green land in this cycle
Things are also more interesting when you have spells like Change the Equation and Anoint with Affliction seeing play in Dimir and Azorious Control
One of the most brutally efficient upkeep triggers you can conjure, it was originally printed as a weaker version of cards like Necropotence or Yawgmoth's Bargain, but its consistency is something that makes it eminently strong even today
Combined with owyn, he can be incredibly absurd, as youll end up tapping down several creatures every single turn and wreak havoc with your army of humans
Most creature based graveyard mechanics (like Unearth, for example) tend to revolve around somehow getting that creature back on the battlefield, but scavenge is different