Playing a binder in your games is a pleasure, Demented.
I particularly like Nyog-Sothep (but then I've always been mad for Fog spells) and I think you did Mordiggian, Yidhra, and the Emerald Flame justice (even if I'm sad there was no Irresistible Dance on that last one).
Maybe I'm just bad at ranking non-spellcastery bindings, but Ubbo-Sathla feels a little weak for a 8th level, particularly compared to Yog-Sothoth (Dimension Door, Greater Teleport, Time Regression, constant Blink) or Azathoth (Wall of Fire, Insanity, immunity to confusion/wisdom drain, that cone of fire/not-fire). Compared to those two, the Unbegotten gets a pair of slam attacks that he has to use, +10 enhancement to str, blindsight, fast healing 5, and immunity to polymorph/poison/75% of critical hits, but runs the risk of his Influence, which is that he can neither speak nor think. Also, he makes Houdini look like a hack magician and he can squeeze through a keyhole, which is really neat, but a little lackluster at 17th level.