The Three Are Within

All gods are within us so the Three of Ys must be there as well although they come to be reviled by most of the characters in Poul and Karen Anderson's King of Ys tetralogy. No god has just one meaning. Therefore -

Lir:
the elements;
the sea from which life came;
pre-human life.

Belisama:
sexual motivation;
aspects of femaleness.

Taranis:
the male response;
control.

We contain:

effects of the elements;
pre-human motivations;
(at least attempted) control.

It makes sense to personify these aspects of life as gods. Our ancestors worshiped them. We begin to understand them. In Buddhist mythology, the Buddha is a teacher of gods and men. Distractions from meditation are natural, not demonic. The Goddess, not the Devil, is within.