I understand the need and use of classes but they do give the sense that the world can be pretty cleanly categorized and cataloged. But what if you could play a weird one-off? This idea is for experienced players who have played all the traditional classes many times.
I'm thinking kind of like Elric, kind of like Ishi. It's a melancholy, last-days type of thing, but also you have abilities and knowledge no one else has anymore. But I don't have those details worked out. I thought I'd throw it out to you.
You could let people pick singular spells (like levitate) that they can do once a day, but then make them take a limitation normally assigned that class (no armor). But that would make the Last One feel pretty familiar, like a hodgepodge fighter-mage. I'm thinking something weirder.
What about mixing abilities with means. So you might have thief''s abilities but they functions as spells (you have to pick a few each day, not all. Do you want to be able to climb today?). Or maybe the fighter's ability to hit multiples of low-HD creatures, but you must petition a power for it, like a miracle.
That's a little weirder. How about we let this Last One use a monster power, like the Umber Hulk look or a siren song?
If the player is experienced they may have always wanted something-- like the beastmaster's ability to see through the eyes of animals. Sure, why not. The idea of this is to let them do something different and new. You could also make a chart with a lot of these possibilities and just roll randomly.
I would say they cannot train anyone in these abilities and, even if they have offspring, the traits will not be passed on. They really are doomed to be the last. Maybe even make it impossible for other experienced players to pick the same set of traits later.
I also feel we could make it a little more doomed by giving them something like a curse (and this could be from a chart too). Something like: you can't die in combat but if you would have someone fighting next to you (or someone you know) dies instead. Though it sounds powerful, that could be a real challenge to play out in a party.
What non-traditional abilities would you want if you had your choice?