Can you please update the OP in regards to Dark Empress Kitana?
I don't know exactly what the requirements are, but "Complete 10 Living Towers" is not correct and I know that for a fact.
I own the game on both consoles, and I've unlocked it twice. On XB1, it unlocked when I did a fatality on every opponent in the hourly tower. (At this point I had already completed well over 20 living towers altogether, including hourly, daily, and premiere, so this might have been an additional requirement.)
On PS4, I have only completed 4 living towers in TOTAL, and I still have it unlocked. Once again, I did 2 daily towers, an hourly tower, and a premiere tower. I did fatalities on every opponent, and it unlocked as soon as I completed the premiere tower.
I believe that the requirements are:
Complete an hourly, daily, and premiere tower.
Perform a fatality on every opponent in any living tower.
Would be helpful if someone who has not done any living towers could test this out and get back to us.
In any case, the info in the OP is wrong. Please fix when you have time.