Help Me Identify a Race -- Floating Armored Fire Demon Things

[wayfare]

Hey All:

I am away from books, and I am trying to identify a race of Demonic or Fiendish creatures to use as low to mid-level antagonists for my pcs.

Here is what I remember for the fluff

They were a warrior race that made a pact with an arch-something and became the mightiest warriors on their world. As payment for their powers, they were later commanded to slay their descendants. They refused and killed the arch-whatever, but were cursed with bodies made out of green acid/fire.

They are a highly lawful race now, and are trying to end their punishment by slaying all of their descendants.

They look like armor clad warriors that lack legs -- their midsections trail off into a cloud of green flames. They also have a sweet crossbow type weapon that fires that acid/fire as a touch attack.

Can anybody identify these things? If so, was anything other than a monster manual entry done with them? Any potentially cool advancement options or clases that could work with their unique abilities?

Thanks for the help, guys!

[Kazyan]

Reth Dakala, from Tome of Battle.

[wayfare]

Thanks!

Any suggestion on how to best deploy them? They are working with a gang of assassins who are trying to take over a major city

[Particle_Man]

The easiest is that they have their own agenda - the city contains a high concentration of their descendants and they plan to a the appropriate time betray their assassin allies and destroy the city with The Big McGuffin.

[wayfare]

Just took a look at them and the CR looks off. CR 4 for a 5hd full initiator with a constant debuff and touch attack weaponry?