Can I evolve Slowpoke into Slowking?

Question

I’m playing on the Virtual Console and am wondering if I trade my Slowpoke holding a King’s Rock to Pokémon Blue, and then trade it back to Pokémon Gold, will it keep its King’s Rock causing it to evolve after I’ve traded it back? Or am I unable to train with Slowking?

Answer 1

You can trade a Pokemon holding an item from GSC to RBY, however, the item won't work (i.e. if you're trying an item trade evolution [Onix to Steelix] it won't work and it won't evolve when traded back.

Source and experience

The game won't prevent you from trading it back, but the item will essentially be deleted, and will not cause evolution when traded back.

Hope I could help!