When using an (Air) Fireball, Liu Kang can combo off of it with Flying Dragon Kick, or . This also becomes a Krushing Blow when done from maximum range. However, this can be difficult to hit confirm and if the Flying Dragon Kick is blocked then you will be punished.
There is way to option select this so that the Flying Dragon Kick will only come out if the (Air) Fireball hits. To do this, immediately input the Flying Dragon Kick after the (Air) Fireball. If the (Air) Fireball hits, then you will get the Flying Dragon Kick. If the (Air) Fireball is blocked or misses, then the Flying Dragon Kick will not come out.