[quote=@Zero Hex]
Medabots have personalities without rare medals, though. Like Prostagma said, rare medals are just used in the anime to have a batshit plot about robot civilizations, justifying power jumps without the need to change the protagonist medabots' parts around and limiting the use of Medaforce to a plot superattack for coolness reasons. Not to mention "oh my dad works for the corporation so I got the one of a kind, incredibly unique artifact usually locked in max security vaults" would probably get the dad fired and the medal repo'd.
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Firstly, what if the kid's dad is involved in the creation of this "rare medal", and those that were involved in the creation got a copy on one each? Also it's a prototype copy, so it can be a house hold jewel much like a grandfather clock etc. Secondly, making it "rare" just means it's unique. It doesn't have to refer to the said "rare metal".
Plot wise, I can patch up any hole that can't make my kid have a rare metal. If it was the case that no kid can get their hands on it, then Ikki shouldn't have been able to get one as well. And so we can justify why we have a rare metal.
Also if you look at the anime you can see that Ikki's Medarot is the ONLY Medarot that seems to act very close to human. Other bots can talk, sure, but none have the rambunctious personality as Ikki's. So my "rare metal" would allow my Medarot to feel as close to human as possible. That's it :P