Here's a good one, Crossover Summoning no Jutsu, summon up Goku or Ichigo or Kenshin to fight for you instead of actually doing any work. Take Oro's idea to a new level of laziness.

And for an on topic ideas,

Bloodline Ability: Flame version of Haku's water control, inspired by Genryusai and Ryujiin Jakka from Bleach