I dont think that were going to see this become a huge staple with decks running four copies, but I do think that multiple decks like Jund, Dredge and Titan will start running 1-3 copies and be able to replace a basic land with it, potentially opening up other removal slots for different cards instead
If you wait until after the declare blockers step, because all combat damage is dealt at once, the Ninja won't normally deal combat damage.
This means it will last long enough to eventually go on the Active Spot and wreak havoc on your opponent
Evolution lines Firstly, you want to keep evolution lines together
To ensure tournament demand is similar, I compare cards with similar Standard metagame dominance percentages, that see no Modern play
you can't cast it without sacrificing a creature, and you can't sacrifice additional creatures