Pitiless Plunderer isnt exactly a paragon of efficiency, but if you are specifically looking to sacrifice a lot of creatures and a lot of artifacts, it has a niche
(If you're playing Planechase, proceed to the next plane.) If you're not playing Planechase, planeswalking won't have any effect
With a haste enabler, like Lightning Greaves, and a way to untap creatures or generate mana on death, like Pitiless Plunderer, you can create an infinite loop of Joo Dees, filling your graveyard with the Surveil trigger
You can choose which side you want to play when you cast it, and this 'unlocks' that door
The 1/1 bears also get another -1/-1 counter, bringing their toughness to zero, and dying as a state-based action (more on why this matters in a bit)