You can't. The special stat being split into sp.atk and sp.def is said to be the reason for this.
posted over a year ago
I thought it was because it's not possible to link a Gameboy Advance with a Gameboy Color. The gameboy Advance cable doesn't work for the GBC considering it's for the next system, and for some reason, the GBC cable doesn't work for the Gameboy Advance. I've tried.