Imo it's better to drop the annihilation/dark priest combo for more utility.
Here's the loadout I'm trying:
Despite it being legit ass, the air projectile at least lets you keep your gigantic ass hitbox in the air for a little longer, and sees some use in some matchups. It's not a "good" move by any means, if your opponent is quick on the uptake then it's a full combo on block at any range except almost full screen. Jump 2 into air hammer controls a good amount of screen space, but nothing amazing. It does have SOME utility though and it's better than nothing, so imo a worthy include.
Second, I go Skewered because IMO is legit the best move that he has at his disposal. One of the best armor breakers in game, so it's a must include to ensure that you get your damage in because it's so hard to open up your opponent.
The final slot is more or less a flex spot (all about equally "good"). Seeking Wrath Hammer is decent, it's one of the better projectiles in the game since it hits the opposite direction so at full screen it becomes very, very fast. It also provides essentially a teleport "counter" for teleports like Scorpion, Noob Terminator.., if they think you're going to throw a spear and teleport and you've launched the Seeking Hammer instead, they will be hit out of their teleport every time.
Second I'd go in this slot is Ground Shatter, even though it's essentially a gimmick it has it's uses especially to end combos leaving the opponent standing and you +7, pretty good in the corner but otherwise it's a overhead/low gimmick with F2 and S1,4.
Last, and most meme-y is Ridicule. Make no mistake there is literally NO set up that allows you to get this out safely but there are cases where the opponent may not be expecting it's use since is basically a dead move. Actually getting the debuff out on the opponent is very, very good though. In most cases it's a better idea to do Ridicule to debuff the opponent's damage because you're extremely likely to get punished for the taunt. The F3,4+Grab krushing blow is extremely powerful but predictably hard to land. If by some miracle you get the debuff on them you CAN combo into the krushing blow for insane damage: 46% with Humiliate and 40% with Ridicule. The only way to get this out even remotely safely is sending them full screen with 2,3xxTaunt at the end of the combo (still -FORTY-FIVE) or ending a combo to send them full screen with 2,1,2 or F4. Again.. You'll prolly die for attempting this, but the benefits are pretty nuts. Especially if you get out Humiliate then land a full combo.
This is still nowhere near enough to make Shao Kahn consistently viable comparative to the rest of the cast. I got EXTREMELY frustrated seeing no changes other than what every character got for him at launch and dropped him, but I've been playing him a bit again. He still struggles hard but has some options to... basically continue to struggle with.