No Mario RPG character is overrated. To be overrated they have to get special attention, appear all the time, and have a ton of annoying fans that makes one sick of a character. Fawful has not appeared nearly enough to be overrated. When I see him shoehorned into everything that says Mario, then I'll believe he's overrated.
If anything Fawful, along with every other Mario RPG character, is underrated because they never use them in anything but RPGs which are sadly not very popular compared to other Mario games.
you do realize that fawful does not NEED more games to be overrated.
overrated characters dont need more games to be overrated to begin with, they can be overrated in one single game, all this depends on one thing: fandom.
and as stated from you, fawful is popular, and he has annoying fans, like you. As being popular, this furtherly increases his chances of being overrated, in which he is.
There are many characters that appear in many games but yet still aren't popular, like daisy for instance, has appeared in the vast majority of spin-offs, yet she still recieves massive hate just for the simple fact of "hey im daisy!".
and just for the record, one character that only appear once in one game, can be overrated.
A great example is kefka from final fantasy 6, who deemed the best villain in the history of rpgs, this long before dissidia(sp?) came out, whom at that time only appeared in that game.
So if you think the only way a character can be overrated is through the use of many games, you are indeed wrong.