"Wet Biscuit McGlee" uses Dragon and a NPC Template to achieve low ability scores but has a bazillion Special Qualities and is CR 17.
Wizard 7 can UMD a Runestaff with Greater Bestow Curse from the Demonologist List.
The setup* He stabs/kills his familiar.
* He takes the Frail Flaw and Quick Trait. (13d4-97 HP, oops)
* He has an additional -8 penalty on attack rolls, saving throws, ability checks, and skill checks.
* Each turn, he has has a 25% chance to act normally; otherwise, he takes no action.
* He is sterile.
* He is blind and deaf.
* Natural 20s are treated as Natural 1s.
* Animals refuse to come within 5ft of him.
* There is a 50% chance anyone coming across him is treated Hostile towards him.
* His Strength, Dexterity, Constitution, Wisdom, and Charisma are all reduced to 1.
Final actionsIn we increase the Wizard's level to 13 and can use Delay Metamagic without further shenanigans.
* His Int is reduced to 1.
* Thieves will steal all his monetary treasure within the week.
* He cannot cast spells.
* All his allies despise him.
So there you go, 5 (or 3) points in his Ability Scores, no usage Class Features or Special Abilities, 1 HP, no items, and all allies and NPCs hate him so no one is coming to his rescue either. WotC Official and lower level too. And if you're undesirably picky "
my build has 1 point in his ability score, you just spammed a single permanent spell of elegance" then well I just gave you ideas to improve now didn't I?