Sealing

Sealing is the ability to seal the energy in objects. For example You can seal someones ki energy in a stone - it's difficult to do, but it's possible. If You do that those person will not be able to use psi powers unless he will break the seal. Of course You can't seal whole energy of something, but only the external layer of ki energy.

You can also seal piece of your energy for example in a sword, so in future you will be able to use that energy for attack or defence. This is a very difficult skill to learn, because the energy is very unstable and it's hard to seal it in anything. But it's passible to do.