Shao Kahn even gets thrown in there a bit too as an option for a few fights, as he falls in the grey area where he was technically not post-game DLC, but was a pre-order bonus that you have to purchase otherwise. Each character gets their own chapter where you control that character in typically around five fights. This includes Shang Tsung, Nightwolf, and Sindel from the old DLC and then Fujin and Sheeva from the new batch. This means that characters like Joker and Spawn will not be involved, but instead the focus is placed on the other DLC characters for the game to date. The main point really for the Mortal Kombat 11: Aftermath is a showcase for the various Mortal Kombat related DLC characters. On top of that, getting so much content with Cary-Hiroyuki Tagawa from the original movie as Shang Tsung makes everything all the better. Having Shang Tsung actually having to play nice here was a fun antithesis to his usual schemes of realm domination. Shang Tsung reveals that Liu Kang also needs the helmet of Kronika that was previously destroyed to be able to shape a new timeline correctly, as doing so without the helmet would shatter the hourglass and ruin time forever.
Mortal Kombat 11: Aftermath is a story expansion that takes place directly after that ending, where the trio of Shang Tsung, Nightwolf, and Fujin show up to stop Liu Kang from using his newfound powers before he could spell doom for them all.