I've often pondered running a PvP campaign for my players, and I've thought back that running SNES 7th Saga's scenario would be interesting.
The aging King Lemele trains 7 apprentices to retrieve 7 powerful runes, declaring the champion as the next king.
The characters are fairly archetypical, and have their own ideals. For the most part they can be mapped to D&D races, classes, alignments.
Wilme the alien: "I can't imagine the power I might have when I get the Runes."
Lux the tetsujin: "During this journey, I wish to find who built us Tetsujins and for what purpose."
Olvan the dwarf: "I'll be young again when I have the power of the Runes."
Kamil the human: "I'm the best suited for the mission: I'll prove it when I find the Runes."
Lejes the demon: "When I get the Runes, I'll be more powerful than King Lemele."
Valsu the human: "My goal is to find the Runes and drive all evil forces out of the world. I'm wondering why Lejes is involved with this mission."
Esuna the elf: "I can take care of myself." (She doesn't say much indeed.)
In the video game, the player needs to team up with another character in order to succeed at some combat challenges.
It also provides unique options for some characters, in terms of social interaction and access to areas of the game.
There are opportunities to acquire some runes through standard dungeoning, and others through social & problem solving.
And most important, each character wants the runes for themselves, with inevitable betrayal.
There are some mechanics to hash out, but I think the scenario could be run pretty well with table & errant participants using daily turns w/fixed options tied to skill checks.
I'll probably shape up a few details I have in mind and update.