This is the "yo secret" of In and Yo (Japanese forms of Yin and Yang. Yin and Yang is Chinese). When an opponent attacks with a lot of force, a lot of In, or Yin, you use Yo, or Yang, to defeat them. Defeat his hardness by using softness. In this way, he will not be defeated by your power, rather he is defeated by his own power. We have been training with this concept in mind a lot in the dojo lately. It is one of the vital concepts of the Gyokko Ryu, and is found in all Ryu-ha of the Bujinkan.
Also bear in mind that this martial wind can also be the divine wind of heaven that is constantly blowing, and one must be receptive to that wind to receive enlightenment from it.
Look for other posts in the future about some of the other scrolls and artwork Soke has painted for me.