On Motare o Kozi, helping Baltia with Eder cannot seem to be done, as his might check will result in a positive, followed by Eder talking. Then the dialogue will end, but Baltia will stay a prisonner of the vines.
It appears to be impossible to free him without doing the might check yourself.
Game version is listed as 1.0.1.0064 RELEASE V2
The game was downloaded on GOG