I was hoping to avoid having to do this, but due to the trends in this thread thus far, I am forced to do so. This is my doomsday post for CAP11. This stage of the CAP is where we "make or break" this concept, and I don't want to break it, so hear me out here. I support...
Motor Drive / Volt Absorb
CAP11 must get one of these abilities or a custom ability that works in a similar manner. Why, you may ask? Think about some real-time scenarios where Togekiss is out. Immediately as Togekiss comes out, the first switch your opponent will always make, if possible, is to Rotom-A, Zapdos, Electivire, or Jolteon. Do you know what all of these Pokemon have in common? Enormously powerful STAB Electric-type attacks. The best we could do without one of these abilities is force ourselves to include a third, Ground-type Pokemon into our core that somehow complements both CAP11 and Togekiss, and the likelihood of that succeeding is basically nil. That isn't a perfect mate as the concept defines it anymore, that's an almost-kind-of-helpful Pokemon you might use with Togekiss.
Now, you could make a case that these attacks aren't so bad if you can switch in a Ground-type. But wait, CAP11 isn't a Ground-type! It's a Fighting-type! Because of its typing, CAP11 loses the ability to switch directly into.... Almost every single Togekiss check or counter that exists. This list includes Jolteon, Rotom-A, Dragonite, Tyranitar, and Zapdos. The only thing its typing helps it switch in on is Tyranitar, who can still Superpower you to death. What does this tell you? Well, it tells you the following...
Without an Electric-type immunity/resistance, the concept will fail.
Okay, maybe that's a bit dramatic, but it isn't wrong by any right. A core requires that at least
some switching go on between the members of the core. If absolutely nothing that checks or counters Togekiss, bar Tyranitar, can be checked or beaten by CAP11, then there is no core. There is only an offensive Pokemon that might sometimes end up paired with Togekiss.
I want you all to sit and think about this for a bit. The Electric-type immunity (or resistance at least, for Christ's sake) is so utterly critical to the success of CAP11 as a "perfect mate" and 2-Pokemon core that I cannot comprehend that we're thinking of other options first.