Yuriko, the Tiger's Shadow!

Yuriko can die as much as she wants. Cost is always 2.

Kill everyone on board with library manipulation and Yuriko Drain. Copy Yuriko with Shakashima for double burn. Grant evasion by discarding Wonder, Flith, Cover of Darkness, Key to the City and Vela for actual ninjas. Use Arcane/Conspiracy for all other creatures with natural evasion. Veil to protect yourself from board wipes since you are super aggro deck. Doomsday into full table burn with all high mana spells or infinite turns (need 8 Mana). Blade of Selves allows you to do ninja shenanigans off tokens!

Doomsday piling: (5 Mana Left) 1. Time Warp 2. Gitaxian Probe 3. Street Wraith 4. Putrid Imp 5. Nexus of Fate

Attack with 1 Ninja Reveal Time Warp, cast it (0 Mana) Start new Turn. Draw Probe, cast with 2 life. Draw Street Wraith, cycle with 2 life. Draw Imp, cast (7 Mana) Attack with 1 Ninja, burn for Nexus of Fate and draw it. Cast Nexus of Fate New Turn Cast Nexus of Fate Attack with Ninja, Burn 7 Discard Nexus to Imp Repeat.