Ryujoji Daigo
Daigo is an ancestor of Shiro
and Hajime and was the leader of
the Ryujoji Shinkage School at
the time Yagyu Jubei was still
alive. Because Jubei's father,
Lord Tajima, got rid of the
other schools in the land, Daigo
got angry and challenged Jubei
to a fight to prove who's the
best. He lost and after he
passed away, all his anger and
vengeance became the spirit
Taiko Daiyu.
 
Taiko Daiyu
This spirit possess the hate of
Daigo and survives only to
eventually see the resurrection
of Jubei and to finally defeat
him. Taiko Daiyu has an ability
to assimilate people and then
make their body and skills his
own for the using. He tried to
take over Shiro's father, Amon,
but was unsuccessful. So, he
took over his first son, Hajime.
After he took Hajime, he took
over Shiro by means of an old
school teacher.