Legendary Creature Human Ninja Commander ninjutsu (, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand or the command zone tapped and attacking.) Whenever a Ninja you control deals combat damage to a player, reveal the top card of your library and put that card into your hand
Otherwise, Discover and Cascade function pretty much the same
Some people see four mana and think its unplayable or mid. I think its one of the best cards in the set, and will be a staple for token decks
You want to build your deck in such a way that you always reveal a Human when you cast this card, and ideally, so that you have choices and can take a good one for the situation
Mana ramp cards like Rampant Growth and Knight of the White Orchid, mana rocks like Worn Powerstone and Sol Ring, tutors like Idyllic Tutor, Demonic Tutor, or Imperial Recruiter, recursion spells like Eternal Witness and Argivian Find, and card drawing/filtering spells like Rhystic Study, Dig Through Time, Wheel of Fortune, and Faithless Looting can all be cards that fit within this category
