"Who" is a question that refers to an entity.

"Am" is the eternal beingness that is here.

“I” refers to this body/mind.

So, if we put these together, we get: An Entity that is Here, in this Body/Mind.

But if we really look, where is the Entity?

Can it be found?

Isn't it experienced here as like a presence without a knowable content - ‘An aspect of all, somehow here'.

An Aspect could be the best description?

An Aspect = individuated yet not separate, simultaneously fulfilling and contributing to all that is within sensing, experiencing and beyond - Body, Mind, Awareness and All.

Manifestation is here, appearing in Awareness.

Mind is not dependant on body for existence, but currently functions with and through it.

Mind is an accumulation of energies, formed around an original impulse of an unknowable Source.

Consciousness is here, having arisen in this mind. 

The unknowable Source may also have what we call consciousness, but this cannot be known by mind.