While @
Shemeska and I often disagree on the value of sticking with old-edition lore, in this case I think we're very much on the same page. I really don't see the upside in tying Asmodeus into the Yugoloths' creation. Honestly, I think Asmodeus already has an unfair amount of focus/influence, as compared to other arch-fiends. He doesn't need any more, and the Yugoloths don't need to have been "devil lite."
But then, I'm also irked that the ultraloth is markedly less powerful than the balor and pit fiend, and that we got mention of the General of Gehenna--who's described as an extra-powerful ultraloth, nothing more unique--and we didn't get Anthraxus. (Who, if we're going back to 1e, was--by XP value--actually
more dangerous than Demogorgon or Asmodeus.
But I'm not bitter.