MK9 had 25 characters at launch and they all appeared in the story, as well as 3 unplayable ones- Goro, Kintaro and Shao Kahn- and Motaro, Shinnok, so 30 overall.
MKX had a few more, as in 24 from the base roster (cause pre-order Goro was not) and Tanya, Rain, Sindel, Baraka, Smoke, Nightwolf...