Lumi

Lumi finds the Keeper by the black water and is the first to name the cause: Malkar tears souls out of the living, and bodies without souls become monsters. She also gives the rule the whole game stands on — wear it down in battle and give the soul back.

She drags the party back to the entrance of a land when the dark overcomes it, leads the chain of the chapter, and stays at your side all the way to the bottom of the funnel.