Satoru, the Infiltrator

The trigger reads like a riddle until you parse the double negative: the draw fires when nontoken creatures enter and none of them were cast, or no mana was spent to cast them. That is a deliberately precise fence built around a very specific way of playing. Ninjutsu returns a creature to hand and puts a ninja onto the battlefield without casting it, so every ninjutsu activation cashes in a card. Reanimation, blink, cheating creatures in off the top: all of it counts, because the common thread is that mana never paid for the body to arrive. Note the word nontoken, which is doing quiet load-bearing work: recursion that manufactures tokens rather than moving real cards (Embalm, Eternalize, and the like) leaves the trigger cold, because the design is tracking the manner of arrival, not the mere fact of it. Ninjutsu in particular spends a card to swap creatures, and this refunds that card, turning the mechanic's biggest cost into an engine. The 2/3 with menace is the connective tissue: it wants to slip through unblocked to enable ninjutsu returns of your other creatures that refill your hand, folding payoff and enabler into one creature. It extends a lineage of ninja-tribal payoffs going back to the mechanic's first appearance, but where earlier ones rewarded connecting with a creature, this rewards how the creature got there: a subtler, broader axis that catches blink and reanimation the older tribal cards never reached.