Parallels again. But when Soh takes damage, so does Yoshiro. Or rather, her concentration breaks?
When Soh's power is stolen, Yoshiro also seems shaken afterwards.
Since the Seethe are said to attack Yoshiro in an attempt to steal her power, Soh...is probably an aspect of Yoshiro.
The Seethe seek out to steal the power of the Goddess but they prefer attacking Yoshiro in battle as opposed to Soh and only attack Soh if Soh attacks first. Bosses are an exception.
Soh can KO but then comes back so long as Yoshiro is still standing.
If Yoshiro falls, it's game over.
Yet, Soh's spirit remains once Yoshiro dies.