Naberious + Soultick. Nuff said.
Yeah, there's actually a ton of stuff like that. Off the top of my head:
Hellfire Warlock (do a bunch more damage with Warlock blasts in exchange for some con damage)
Ritual of Shadow Walking (as earlier)
Psionic Sinew (Gives Claws of the Bear for one point of dex damage, and gives 3 temporary hitpoints for a minute for the same cost)
Soul Tick (Does 1 point of con damage per day, and will throw in a little extra if it doesn't like you, but auto empowers all death, evil, and negative energy spells)
Dark Speech (Take 1d4 Charisma damage to cause a host of interesting effects, such as causing fear effects, increasing the caster level of evil spells, increasing the caster level of evil items, etc. Also, take 1d4 con damage to make a hive mind out of vermin)
Corrupt Spells (There's a ton of them, and all of them have a side effect of stat damage)
Words of Creation (The good version of Dark Speech)
Sanctified Spells (The good version of Corrupt Spells)
Tainted Sorcerer (Take con damage for free metamagic, as much as you like!).
There's a good reason Binder 1/Archivist 3/Anima Mage 10/Tainted Sorcerer 1/Tenebrous Apostate 5 is basically the ultimate build... and Naberius is at the core of that power.
JaronK