TCW watchers will remember the ghost of qui gon sends yoda on an epic quest- he meets many witchy types but is sent to the wellspring of life - seemingly the birthplace of the Force (but maybe the birthplace of the light side)
It could be that Baylan is looking for- and intends to destroy- the dark side ‘wellspring’
The rumors involve that. They say it's going to be Abeloth, the mortal adoptive mother to the daughter and son and wife to father. She's pretty much more powerful than the 3 of them combined, but was trapped over there.