>>58278837ok so we've cleared the conceptual gap of "stones can be whatever energy"
now the issue is with the gimmick. Uh, why does it matter that there's only one outlier? there are tons of one-off weird things in pokemon. What clearly happened is that they put the oval stone in, decided it was something to resemble the egg chansey would keep, then they said "hey what if instead of making you use the stone on happiny, we had her hold it and level up with it to cause the evolution"
If I understand correctly, in diamond and pearl, you could indeed select "use" on the oval stone and it just would never let you actually use it on anything, acting like any other evolution stone but not actually having any "compatible" mons, and only working by the later giving it to happiny.
