In trying to understand your concept of soul merge as merging with our Higher Self, is it like uniting all the fractured parts of the personalities or integrating them back together. I am wondering if it has to do with discovering aspects of our personalities we are not aware of and integrating them again with our higher self. Also, does the symbolism in the Adam and Eve story have to do with the separation from our higher self? Regarding twin flames, is our twin just our higher self we separated from or is it another being.
In its simplest explanation the Soul Merge process is merging the True Self or Higher Self into every aspect of who we think we are at all levels. The Soul is eternal and invincible and exists in a unitive state of awareness. The merging process actually causes the Soul to replace the illusions held in the ego-mind and consciousness. It is a transformational process that eventually leads to a person becoming a full expression of their Soul rather than all the separate components of their ego-based personality. The soul in this context includes the underlying true essence of our being which is one with all existence. The Soul Merge process eventually replaces all the ego-based personality traits with the essential purity, integrity and goodness of the Soul. The Soul is primarily composed of deep love and radiant light which manifests as every wonderful quality and aspiration of the human spirit.
Multiple personalities and fragmentation is another subject. Personality components are aspects of the ego identity. The ego is an accumulation of identities, beliefs, perceptions and reactions that are totally distinct from the Soul. In the Soul Merge process the Soul can merge into these separate components in which case the illusions of separation disappear and the component diminishes and eventually ceases to exist. There is never a sense of loss in the Soul Merge process. In fact, quite to the contrary there is always a sense of expanding into something more than we thought we were because we are moving into greater states of unity consciousness and enlightenment.
The Adam & Eve metaphor can have a number of interpretations but they tell the story of the soul becoming separated from the Divine. Twin flames is a theory that an individualized soul has two aspects composed of opposite polarities. This is not a universally held belief and is not supported by traditional religious texts, but is mostly an outgrowth of channeled information. Those who have deep connections with their mates often believe they are twin souls or twin flames, but each is a complete soul and not in need of the other to become complete. When two or more souls are similar there is a strong familiarity and deep love that is shared. I have worked with thousands of people at a soul level and I have never had the impression that any of them were derived from splitting a Higher Self in two to create a twin flame.