I've seen the description, though I don't know the specifics. It might be an interesting change of pace, but I don't think it would be appropriate as a standing option. My reasons are these:
1. Unlimited power – the warlock never runs dry.
2. No cost associated with magic use – inborn power doesn't feel to me like it should risk corruption or catastrophic failure.
3. Too much direct destruction – Conan games should remain free of artillery mages, so Eldritch Blast would have to be nixed.
The warlock would make a great climax villain, however; a wizard who did the right rituals and sacrifices, or found the right relics (Hand of Nergal, anyone?), could achieve this seemingly unstoppable level of power, and the PCs would have to destroy him before he could consolidate his armies and take over the world. Even better, his power could be turned inward so he'd destroy himself – that would be the terrible risk all sorcerers face.
Of course, this is just the opinion of somebody who has still never played even one session of Conan.
