..the Could-Have-Been-King. Imagine if Davros pulled an alternate Doctor whom he convinced to side with the Daleks. I doubt that this is the case but it would be neat.
I believe - at least given the fragment of dialogue from the mystery Doctor - that aligning with The Daleks was never part of the plan or indicative of his big secret™.
The Could Have Been King with his Army of Meanwhiles and Never Weres was implied to be on the side of the Time Lords. Also, at this point there is no evidence the Hurt Doctor sided with the Daleks. That's just popular speculation.