How to build a Masochist

[BigP4nda]

Okay so I am GMing and trying to make an NPC. Its a race I made called Vanaga'iiros, basically snake-like humanoids who resemble humans (actually resemble vampires more) and have very toxic blood.
The NPC I am making is a masochist who throws herself at the foes sword basically so that she can poison him, she also does things like cutting herself to put the blood on her blade (stabbing herself usually considering she wields a rapier) and etc.
My question is what are feats that would fit a character who loses a lot of HP in a battle, I know about the Diehard and Toughness feats
Perhaps anything that helps prevent crits, heals damage, and perhaps also anything that boost combat abilities while low on HP

Thanks in advanced.

[Arachnofiend]

The good ol' "DR into eternity" Barbarian would be good for this. You want Unbreakable Fighter 1/Invulnerable Rager X. Take Stalwart and Improved Stalwart and ignore your AC completely.

[LoneKnave]

There's the Pain Taster PrC as well.

[Petty Alchemy]

If you're mixing 3.5 with your Pathfinder, Crusader's got Steely Resolve. I'd love to see something like that in Pathfinder.

[BigP4nda]

I feared the options would resort to specific classes :| I want to keep her as a rogue because it fits her playstyle and characteristics better while still giving her access to rapier as well as perform and stealth (Going for shadowdancer)

[Bigdaddyjug]

It's probably not going to work, then.

[BigP4nda]

What if I made a Masochist archetype?
Trapfinding -> Resilient: Add half your level to saves made to resist pain and death effects.
Trap Sense -> Fast Healing: 1 at 3rd - 6 at 18th

???

[grimdog73]

What about rogue/monk? You could use a grappling style instead of the traditional type of combat.

[Bigdaddyjug]

I will say that the Pain Taster PrC advances sneak attack as long as you use a whip. For somebody who's supposed to be a masochist, using a scorpion whip as their weapon of choice is certainly thematic. You could flavor it as he/she self-flagellates in order to put his/her blood on the whip to use as a poison.

And all of the pre-req feats are definitely thematic of a masochist as well, Diehard, Endurance, and Great Fortitude.

You could also give him/her the History of Scars feat.

[Bigdaddyjug]

Now you've got me wanting to make a rogue who uses a scropion whip and goes into Pain Taster at level 6.