On the other hand, Kadena, Slinking Sorcerer and Otrimi, the Ever-Playful actualy want to enforce a theme but almost too strictly. There aren't enough Mutate cards for Otrimi and I really just don't like Kadena though it otherwise fits the criteria I generally want a general to meet. Zaxara, the Exemplary sort of fits into this category as well and, again, just didn't seem all that interesting to me.
Sidisi, Brood Tyrant is a deck I had built a while back and one that I had a lot of fun with. Out of all the Sultai generals, she is the most fun and really hits a lot of things I care about. The problem with her is that she plays in a similar space to Karador. And, while not a huge issue, she was pretty easily shut down by things like Anafenza, the Foremost. I just didn't want to have another graveyard matters deck in the rotation.
I still tend to revisit the idea of a Sultai deck every so often but with little success. With the release of more partners, I decided to take another look at that route since the Sultai Legendaries aren't what I want. I thought Ikra Shidiqi, the Usurper could provide some fun games. While she doesn't really do much to lend herself to a theme beyond "gain life" it is still the best of the ones I could see.
For a Partner I basically narrowed it down to two choices: Thrasios, Triton Hero and Sakashima of a Thousand Faces. I ultimately decided on Sakashima because Thrasios really isn't all that fun or interesting to me. Ramp and then draw/ramp more is boring. And Sakashima at least sort of lends itself to a bit of a clone theme which I haven't really done before. Ephara has a few, but not much.
But then, as I put that list together, I realized it was mostly just clones and Ikra Shidiqi wasn't actually contributing much. Based on a suggestion below, Volrath, the Shapestealer became the number one choice to helm the deck. So, with that, here is the list I am going with:
The idea isn't all that complex: I just threw a bunch of clones in with some big creatures that are worth cloning and ran with that. There is a fairly delicate balance of clones to actual threats and Spark Double is one of the more noteworthy exclusions because of this balance. It only copies my own stuff and I don't have planeswalkers so it ends up being pretty much the same thing as Sakashima of a Thousand Faces without the ability to benefit the rest of my clones in a general sense.