Y'all may disagree with this but all Karnak needs to be crazy good is an update (a little number tweak and a little more utility). Before going deep let me post his current ability and I'll point out things that could be added to make him OP


First his attack rating can be boosted a bit, and his passives are alright not going to lie, when he is focused he crits quite a bit and it is a big boost, another thing I would add is anytime he is focused he gains a true strike preventing evade and auto block ( meaning if you get focused either through Sp 1 or after waiting 9 secs you can keep it for the whole fight if you don't get hit, juicy right?).
The physical resistance is alright and I'd increase the class reduction to 1% for for every 1 seconds another thing I'd do is increase his Critical damage rating by 50 for every hit on combo meter( I'm sure kabam can balance that number if its too high). With this he becomes a champion that rewards being able to hold your combo( boosts his damage, and focus), I'd also give him indefinite combo shield buffs on heavies like G99 but capped at 4 ( buffs so he can deal with nodes that need buffs).
Now onto specials, specials add combo to the combo meter based on which one used. Sp1 adds 50, Sp2 adds 100 and Sp3 adds 150 (this can be balanced by kabam)
Special 1 remains almost the same but I'll make him get 3 indefinite cleanse anytime he use it. Max Stack: 3( don't forget he gets true strike when focused now so the 2nd like should be ignored)
Special 2 Inflicts 5 bleeds each dealing 4000 damage(assume this is a 5* rank 5)over 30 seconds (5 bleeds for nodes like Diss track and I made it long on purpose and I'm sure you know why already)
If this attack is used immediately after charging heavy consume all combo in the combo meter and increase attack rating by 50 for each hit in the combo meter (can be balanced by kabam)
Special 3 reduce ability accuracy by 80% for 60 seconds
Signature ability remains the same, and I'd also add enemies get their Defensive ability accuracy reduced by 30% when knocked down for 10-25 seconds