If Pokémon Talked (Generation I)
Starlight Hope for Clefairy/Clefable (Female)
Clefairy and Clefable are Fairy-Type Pokémon (formerly Normal-types). They are shy and timid Pokémon. They do not like fighting and prefer to live in quiet areas, so I would expect to have a high and sort of quiet voice. But also playful sounding at the same time. Clefairy would sometimes speak in 3rd person, and Clefable no longer have the 3rd person way of speaking, and would speak in a more mature sounding voice than Clefairy.
Clefairy: What a perfect night to start singing and dancing! Clefairy loves it so much!
Clefable: I was lucky enough to find a moon stone back when I was a Clefairy.
That's okay. I just noticed recently Clefairy and Clefable actually kind of have similar sounding voices in the actual anime. I would just say that Clefable would sound similar but more mature for this.
I still loved this even if Clefable was not added. They have similar sounding voices anyway, just Clefable sounds more mature. But either way, you may be the only one, but I am very satisfied with this audition already. You are officially cast for this role as well! :)