If evolving Pokemon with an item is not yet a clear process to you, here’s what you need to do:
These items are used in addition to pre-existing Pokemon candies to evolve from first-gen monsters.
The items are:
*** Sun Stone**
*** King’s Rock**
*** Metal Coat**
*** Dragon Scale**
A Sun Stone will transform Gloom into Bellossom when coupled with 100 Oddish candies.
Combining Seadra with 100 Horsea candies and a Dragon Scale gets Kingdra, its final form.
Porygon becomes Porygon 2 with 50 Porygon candies and an Up-Grade.
Both Poliwhirl and Slowpoke use the King’s Rock to evolve, and Onix and Scyther rely upon Metal Coat.
When evolving Onix or Scyther, all that’s needed is 50 of their candies and a Metal Coat item.
When it comes to Slowpoke and Poliwhirl, however, things are a bit different. Both Slowpoke and Poliwhirl have two different evolutionary forms, including the first-gen Slowbro and Poliwrath.
To get Politoed and Slowking — the new forms of Slowpoke and Poliwhirl — players need a respective 100 and 50 candies, as well as the King’s Rock item.