Quote Originally Posted by Assertn
Ugh....Archie....
Invisibility is just another supernatural ability. Mimicing identities is the same basic idea. None of these things counter my initial point that devil fruit abilities don't portray artificial / man-made things.
Fine, if that's how you want to play it

Supa Supa no Mi - The fruit eaten by Mr. 1 that allows him to turn his body to steel. As far as i know, steel can't be found in nature and must be created by man

Bomu Bomu no Mi - The fruit eaten by Mr. 5 that allows him to become a human bomb, another human creation ( although i guess you could make the point that nature could combine its elements to create a bomb aswell even without human interference )

Shari Shari no Mi - A fruit eaten my a marine officer that allows him to turn him arms and feet into wheels, perhaps one of humanity's first creations

This is an interesting fruit since it was introduced in the manga during the Enies Lobby escape but was never shown in the anime. Since the event has already happened, i wouldn't call this a spoiler.

Details here - http://onepiece.wikia.com/wiki/Shari_Shari_no_Mi