Whenever Nashi deals combat damage to a player, you mill that many cards. You may put any number of legendary and/or enchantment cards from among them into your hand. If you put no cards into your hand this way, put a +1/+1 counter on Nashi.
Cheat Nashi into play with ninjutsu off evasive early creatures, connect for combat damage, and mill yourself to dig out legendary permanents and enchantments while growing if the mill whiffs. You build a self-mill/value engine that snowballs into a wide legendary/enchantment-matters board, then close with a big menacing Nashi or assembled combo.
Two-mana commander that can recast cheaply and provides repeatable card advantage off combat damage
Menace plus ninjutsu makes connecting reliable and dodges single blockers
Rewards a high density of legendary creatures, planeswalkers, and enchantments with free recursion from your graveyard-bin mill
Self-mill enables reanimator and graveyard synergies as a bonus payoff
Card advantage is gated behind connecting in combat, so good blockers or sweepers shut it off
Mill can dump bombs you can't easily get back if you lack reanimation
Fragile body (2/2) that dies to most removal and must be redeployed
Two-color Dimir lacks efficient ramp and struggles against fast combo without interaction
Yuriko, the Tenured Humanoid
Another evasive ninja that loves the same shell and adds a punishing damage clock alongside Nashi.