>>44168438People always say to combine Ground and Rock into Earth, but the real big brain move would be to combine Rock and Steel into Mineral.
Realistically Rock was originally supposed to be what Steel is now, but then Steel came along and did everything it does way better. They are in many way similar, and also happen to both be "physically hard material that comes out of the dirt".
IDK what the weaknesses would be, I'll let you argue that yourselves. It should be a balance between the two. But if the Type matchups are anything remotely like what Steel's were, Rock Pokémon are now a fuckton better.
Also yes I know steel is an alloy and not a mineral like iron is, but there's no perfect word for it that I can fine.
