Ford, Wade
A tsunami is coming, and you want to walk over it, so you have to ford it. You don’t walk across a tsunami, you wade across it.
Imaging taking your shoes off, hiking up your pants, and holding all of your things above your head as you ford across the tsunami.
しょう
わた
None
Your ability to ford this tsunami impresses everyone who witnesses it, especially the Shougun (しょう). Now that you've taught him a tsunami can be forded, he's going to start sending his troops through them instead of waiting for them to pass.
Your new fording techniques have increased the Shougun's military power! Congrats, I guess.