I've seen that there's the amiibo-specific party mode in MP10, but how does it work exactly? Is it worth getting a MP amiibo for that mode or will the Mario amiibo from Smash also work fine? I'd prefer to not have to buy anymore if I can just use the one I got.
The duplicate characters are equivalent in terms of functionality, but the NFC chip only has memory for one game. So you will have to erase your Smash data if you had that to use the same Mario Amiibo in MP 10.