Keiko was a member of D'Hoffryn's Magic Council. Keiko was a ghost and presumably represented spirits. She was reputed for killing all who watched her black and white video. Comically, Keiko explained that it was her wedding video and that her husband drowned her because he hated the videographer's choice to shoot it black and white - which Keiko thought was beautiful.
After the restoration of magic, Buffy and the other Scoobies created a series of rules to write in the Vampyr book, where each member of the council would have a particular ability that they could use against those who would threaten Earth's balance.
Keiko's ability was to absorb and redirect the kinetic energy of an attack.
However, she was killed by D'Hoffryn, who was planning on using the magic law for himself. He worked around her power by drowning her.
Behind The Scenes
- Keiko is a clear nod to Sadako Yamamura from the popular Japanese horror francise The Ring.