Interesting NPC/quest idea

[Alucard 109]

I had an idea for an interesting NPC that I was hoping you all could help expand on.
What if there was an exceptionally powerful high level NPC who had multiple Greater Bestow Curses cast on them, reducing all of their base stats to 1. This NPC would need to be assisted through a series of seemingly (but not actually) impossible challenges until they were fully restored, in order to aid the party with a task beyond their means.
There are a couple of things I'd like help with.
What would be a good NPC class/build for this? Potentially powerful classes/builds that suffer from severe MAD would actually be preferable to things like wizards (who would only need to complete one or two tasks to be at almost full power)
I'm not sure what level party this would be good for though, because if I'm too low, the NPC would be better off doing it themselves, and if I'm too high, the party might not think the effort is worth it.
I wouldn't mind some ideas for "impossible" tasks either

[Crake]

Keep in mind just what having a 1 in every stat means: 1 strength means they cannot move with more than 10lb worth of stuff on them, 1 dex means they are clumsy as all hell, having a base AC of 5, practically barely able to move, 1 con means they will have almost no hp, and will be very sickly, quite possibly dying to just a simple cold, 1 intelligence means some of the most basic of animal intelligence, 1 wisdom means they're barely capable of percieving and understanding the world around them while finally, 1 charisma means they have little to no sense of self or understanding of the separation between them and the world.

Such a character wouldn't just need help doing the tasks, they'd need help simply existing, you're basically looking at a person who is wheelchair bound with cerebral palsy, parkinsons, auto immune deficiency, who's been lobotomized and has severe cataracts and partial deafness.

[Alucard 109]

Such a character wouldn't just need help doing the tasks, they'd need help simply existing, you're basically looking at a person who is wheelchair bound with cerebral palsy, parkinsons, auto immune deficiency, who's been lobotomized and has severe cataracts and partial deafness.
I'm aware of that, but after a certain level difference, they would STILL be a credible threat, even with that (base saves, BAB, class features, hit dice, ECT). Not to mention, they would be getting more and more powerful with every task completed. My problem is balancing the initial difficulty with the end difficulty, while keeping things interesting throughout the whole thing

[Kayblis]

Can you clarify a bit more about the execution?
If I get it correctly, you're doing a variation of the "build the MacGuffin" hook, kinda like collecting many red crystals and glueing them to a crystal crown that gets stronger with every crystal, then killing the BBEG with a red crystal ray. Is there any special reason for that? Any plot line related to the person? That could work to start the basis of the NPC. As a rule of thumb, ToB classes are great classes to use when you need a powerful character with no spells, but in that situation you might be looking for classes more like gishes. Look up the Duskblade, they have some nice tricks to act as a high-level character. As they're supposed to start with 1 on everything, they can't cast at all - which can prove to be a nice surprise! The party gets used to the idea of a strong melee combatant(full BAB, decent HP), and then when that INT gets above 10, the REAL character comes to light. One-liners galore ensue.

[Alucard 109]

"build the MacGuffin"

Look up the Duskblade

Yes, almost exactly like you described. (I wasn't aware of that particular plot hook idea until now. I was planning on having the requirements for breaking his curses be that he must preform tasks that SEEM impossible with his stats, (and probably would be, without help) but are in fact only very difficult. An example I had for one possible task would be "uproot a large tree without the aid of man or magic" it SEEMS impossible at first, but with the aid of technology or trained animals, it's doable. (I thought this was too easy, but I think I could make it workable if I adjusted it a bit)

I'll definitely look into the duskblade