The Great Father Philaha (also known as Filaha in the SNES/PS version) is the patron god worshipped by the Order of Philaha. He's believed to have fathered six goddesses of elements (Hahnela, Vaasa, Xoshonell, Lyuneram, Nestharot and Greuza), and resides in heaven with his holy servants, where he welcomes the souls of the pious, noble and just.
It may be possible that he's the same being as Filarhh, the sun god worshiped by Lodisism.