This thing was written in a way that made it very hard for me to follow, one thing i didnt understand were these "echo's who was actually saying that?, it has me pretty confused, could someone give a small summary of it?

Yes, it was written to convey the overwhelming feelings of love, longing and frustration. The perspective shifts between Deionarra and one of TNO's earlier incarnations, which is evil and calculating. It also provides a reaction from TNO's current incarnation, frustration because of his past incarnation's crimes, that's why it's difficult to follow.

Basically, it's a dialogue between TNO and Deionarra in which he tries to manipulate her into loving him. The sensory stone shows you the experience of her overwhelming, desperate love and fear of loss and abandonment, and at the same time TNO's frustration with her whining. It ends in Deionarra suggesting, or rather, insisting on accompanying TNO to the Fortress of Regrets, which is what he wanted from her in the first place. Maybe someone else can provide the full story, a I'm typing all this from memory. There's a full transcript of that sensory stone in the Planescape Torment book that can be downloaded among the bonus items at GOG.