With Duskmourn having so much inherent surveilling and other ways of filling your graveyard, while also having a big chunk of enchantments (or creatures that are also enchantments) you'll most likely have something to return back to hand
Apex Predators It's no surprise that with all this power, the mime is at the top of the food chain
Necropolis Regent is a good card to have by these saboteurs since your army can get big quickly
Most famously, using this to reanimate Worldgorger Dragon creates a loop which flickers every other permanent in and out of play forever (or until your Piranha Marsh has triggered enough times to drain their life total)
Being able to play the discounted cost in early to mid-game provides a ton of advantage which can set up for quick wins as other opponents struggle to keep up
Drawing a card as well means you wont have to worry about being down a card either, which can make the difference in a tight game While nowhere near as busted as Kodama of the East Tree, Kodama of the West Tree has some potential to rocket you ahead or act as a finisher in the right deck