Salvia divinorum breakthrough experiences are life altering. Nothing quite like the experience where you're convinced you died and scenes from your past appear.
Sometimes, the Ego is disabled and you calibrate to being a point of energy with no body and no sense of "I-ness". You just "are". Then you come back a little while later and realize how heavy life actually is, and how useless thought-fomented emotions are.
An amazing feeling from Salvia "pulling you in" to a deeper experience is part dread, part racing thoughts, and part exciting, with a physical sensation of a hand grabbing you by the brain (note not scalp feeling, but inside the head) and pulling you backwards.
Of course, a breakthrough exp is not always how it goes. I think it depends on potency, quantity and current biochemical state. At the lowest level you see aspects of the world move and warp in somewhat logical ways, like the pattern of bathroom tiles looking like trails of ants or something like that. Things people say to you are mistranslated into completely different things, for example a friend of mine had asked about going to another friend's house and I heard him ask to clean up after the dog with a broom, when he had no dog at all.
Sometimes you end up with extremely humourous alterations of reality. I did it with an olive skinned friend once in his sky blue painted bedroom and he morphed into an old native American with the feathered head dress rising up out of the ocean, looking disapprovingly at me. One of the hardest times I've laughed lol.
My2c at least, the experience is different for different people. Ego-heavy people I've taken through these trips often feel pretty traumatized for a while. I can share a lot more about this plant for anyone interested.