The nine stages represent different stages of evolvement with more cetasika. Each stage has an increasing number of cetasika as that initial “citta” stage gets increasingly contaminated.
– The final stage of vinnanakkhandha is quite complex.
We never experience the intermediate stages starting with the “citta” stage. We only experience the final stage of vinnanakkhandha.
– This evolvement in nine stages is discernible only to the mind of a Buddha.