I'm not an expert on Green Lantern rings, but it was my impression that they mainly dealt in force fields.
What Spawnie and DemonicGambit are talking about is different. In the episode of Buffy they mentioned, an unpopular, depressed young man cast a spell that changed people's minds and also his own physical abilities to become someone he wasn't.
This is closer to something that Franklin Richards could accomplish, given time to master his abilities. Lord Ryugen mentioned Proteus's powers. What he really wants is Franklin Richards's powers. Proteus has to jump from body to body, murdering his hosts, and has an intolerance for metal. Franklin Richards also has the ability to reshape reality in accordance with his imagination, plus powerful psychic abilities, and he doesn't require a host body. That's the power package you really want, if you want to remake the world in your image.