So Shao Kahn's hitboxes are essentially bugged. Until NRS fixes him, he's bottom tier, maybe even the worst character.
Shao's standing 1 whiffs on everybody's crouch block and on smaller hitboxes, standing 2 and 3 will whiff too. All these are highs and shouldn't be like this afaik. That basically makes it impossible to pressure anyone who knows what they're doing.
S1: Whiffs on entire kast crouch blocking. Maybe intentional? But....
S2: Whiffs on all female crouch blocking and Noob Saibot.
S4: Whiffs entirely on Noob Saibot crouch blocking and on all females at max S4 range. Up close it hits all females.
F2: Whiffs on all females and Noob crouch blocking. Whiffs on every character at max F2 range.
S2 whiffs on more characters crouch blocking: Erron Black, Kollector, Johnny Cage and the list goes on.
This is a huge problem for the character given how the game wants you to pressure people and I have no idea how it wasn't noticed by NRS.