Sei Hei Ki
Sei Hei Ki heals by dissolving the blockages between your human self and the Divine. It is used to calm the emotions.
To use this symbol, just draw or visualize it and chant its name three times.
If you are combining it with the Cho Ku Rei symbol, you would first evoke Cho Ku Rei, then Sei Hei Ki, and Cho Ku Rei again. This can be understood as causing the Cho Ku Rei energy to amplify the emotional healing power of Sei Hei Ki.
Other uses for this symbol include drawing an object to you. This can be done by visualizing the object and evoking the symbol in the manner described above. It works by drawing the spiritual energy of the object to you, which will eventually cause the physical object to appear as well.
Hon Sha Zi Sho Nen
Hon Sha Zi Sho Nen heals by expanding the Mind and Consciousness. It can also be used to send Reiki across Time and Space. This is the symbol needed to perform Distant or "Remote" Healing.
To use this symbol, draw or visualize it and chant its name three times, as you did with the others. If you are using it for Remote healing, you would first evoke this symbol, then evoke whatever symbols are needed for the type of healing you wish to perform. For example, to perform an amplified Emotional Healing for someone remotely, you would evoke Hon Sha Zi Sho Nen, then Cho Ku Rei, Sei Hei Ki and Cho Ku Rei again.
This symbol can also be used on its own to heal the Mind. It works by expanding the consciousness of the individual for whom it is used. It can be used on its own, or amplified in the manner described in the section on Sei Hei Ki.