Alu-fiends and cambions are results of mortal breeding with tanarri.
are they Tannaric enough to be promoted?
Alu-fiends and cambions are results of mortal breeding with tanarri.
are they Tannaric enough to be promoted?
According to this page, "A rare few alu-fiends undertake great rituals to advance themselves to full succubi or even lilitu". So it would appear that they, at least, can integrate themselves into the usual tanar'ric hierarchy. I haven't heard of promotion among cambions yet, but I would rule few things out when it comes to the Abyss.
Even if they couldn't do it by the conventional method, it seems easy enough for a Tanari Lord to have a particularly favored cambion/alu-fiend servant transformed into a full demon via Polymorph Any Object.
Anything can happen in the Abyss
Promotion would sort of indicate a higher power bestowing a title onto his or her servant. While there is a theory in Faces of Evil that says that Balors and Nalfeshnee govern the promotion of tanar'ri, that's probably way too lawful to be true.
Other theories are that belief in their strenght eventually grants them their strenght, and hence a higher station (Faces of Evil), that the Abyss simply promotes at random when it feels like doing so (Faces of Evil and sources that mention Turgalas), or that any demon can ascend by harvesting souls (4e Demonomicon).
Of course, the likelihood that a cambion or alufiend survives long enough to ascend is pretty slim. The Abyss is faily dangerous, so there always the chance that an accident happens, or an 'accident' happens, or they simply get in a fight and/or get eaten at random, if they're not simply being drafted for, and die, in the Blood War.
And after they're dead I imagine they simply reincarnate as larvae or manes and start their fight for ascension anew, but this time they're simply one of the billions and not unique half-mortals anymore.