What do I do with the dubious disc?

Question

I know it sells for a large price but i have a feeling its used for SOMETHING important for evolving or something.

Answer 1

You trade a Porygon 2 holding the Dubious Disc. Then it will evolve into Porygon-Z.

Comments

i thought it was up-grade

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No. That's from Porygon to Porygon 2.