Summary & Playstyle
Khan's main strategy is pressuring your opponent until their defense cracks, allows you to either perform Khan's basic combo or a super combo.
You should usually approach with 2A or j.C since most of the damage will be dealt through them and Khan's BnB combos, although you still have some other choices. Make good use of Khan's tools, like his anti-airs (5S, 5B, 623A/B/C, etc.) and in some cases even his Counter, as it can win you a round if you manage to catch a good move, but it may also cost you a one if it whiffs.
I'm sorry to say that you'll find yourself playing dirty as Khan, surprise supers, tick grab spam, hyper hop spinning, and abusing Khan's excellent back dashes are all necessary for his own matchups. If you enjoy characters that have to approach each matchup differently you'll love Khan. Khan doesn't have consistency because of how weak he is; he bends to his opponent's character.
Unfortunately, a lot of Khan's tricks don't work on experienced players. You need to ramp up the frequency and variety of Khan's tricks, outplay your opponent using reads, use mixups, block everything, guard cancel, etc. and pray to come out on top versus an experienced player.
Ultimately, Khan is a fun character who is unfortunately unfinished. Khan is an easy character to pick up, but winning as Khan takes experience and execution. Be happy with every win you garner as Khan, you outplayed your opponent.
Grabs
Tick grabs are surprisingly easy and useful for Khan, not for damage, but for cracking defenses, turning stand off and maneuvering characters into the corner where Khan wants them due to the long throw. Note that Khan's throw has a soft knockdown and does poor damage.
(Tick grabs can be done by hitting the opponent with a move that has a lot of hitstun and then grabbing them quickly after they recover from it. Tick grabs are harder to tech-grab than normal grabs)
You can either use normals to tick grab or you can just empty hop and grab the opponent. (second option is more preferably used in okizeme)
Moves you can tick grab with (from easiest to more difficult):
d.2A
d.2B
j.C
j.A / j.B
j.S
Khan's grab is easily punishable as it gives you 14 frames of disadvantage after the opponent techs.
However, there are some ways around this for Khan to avoid getting punished.
You have to roll in a certain 1f window as it gives Khan i-frames to avoid getting hit.
Do not always rely on this, however. As there are people who are willing to punish you by grabbing your roll.
For example doing empty tandem after teching and grabbing Khan while he is rolling, or for some characters who simply can't punish Khan's grab in general.
Okizeme
Khan has a few tricks for his okizeme. First one can be done by just simply landing a j.C as they get up. Simple and effective, if it lands you can go into any of Khan's combos, even another knockdown. It's also the safest option on block. Mix it up with empty jump 2A. You can go for an IOH (Instant Overhead) j.C, then cancel it to j.S to escape in case the opponent was about to punish you.
Khan's Okizeme Guide
Another option is to simply grab them on wakeup. You can further expand on this by backdashing, waiting for them to wakeup. At this point your opponent will think to throw out an attack instead of an anti-wakeup measure so you can dash in with 2C to knock them down again, 2A to tick grab them or 2A/2B to combo into 214AA.
After landing a hard knockdown against characters that take a longer time to wake up, you can attempt to do a long jump behind them and try to give them a sneaky low or high from behind. If 214+AA stand crashed, you should have more than enough time to pull this off.
You can also do the Counter Learning move after the opponent wakes up to catch them but it is extremely unrecommended, as there is a chance you might die if it doesn't work out.
The last okizeme option is using meaty okizeme with 5C, 5B or any other normal that has a lot of active frames. In case the first 5C whiffs, you can still do the follow-up 5C>5C to catch the opponent if they were trying to whiff punish you. But if it connects or if they block high, following up with a [4]6+C may surprise them and result in another knockdown.
Neutral
Khan should only use short hop j.C, dashing 2A, and 4B for the neutral game (and in some safe cases 5C) meaning most characters will beat him in the neutral game. However, it may be beneficial to play in the neutral game with characters that are simply too powerful for Khan to risk closing in on. (e.g. Vice and Jotaro)
Charging is a very good idea in the neutral, [4]6+A/B into 623+C is often Khan's best punish and can open the way for Khan to start comboing. A nice trick is to [4]6+A/B underneath your opponent if they jump high and 623+C in the other direction to catch them in an air cross up.
Khan's defense is abysmal. He has no defensive options and the best option is to usually to push block like a madman if you're caught. Both his roll and guard cancel are average meaning Khan will be caught out often. If worst comes to worst and Khan is caught in the corner, super jump over your opponent and spin as far as you can.
Your best chance for getting an aggressive opponent off your back is either jumping back and using j.B into S to retreat or going for a tick grab to reset to neutral.
In some rare cases, his Counter Special can be very useful. Landing it is difficult, but if you tag the correct move e.g. Shadow DIO's 5C or 5S you will really slow him down and sometimes it can slide the game in your favor. Still, it's a really risky tactic as the counter has abysmal endlag if it doesn't work.
Mobility
Phew, finally a definitive strength for Khan.
Khan's S spin offers him unrivaled mobility in the air, possibly only contested by Kak and Ice's IAD. The speed at which the spin moves is determined by the direction Khan jumped in and the speed at which he did his jump, so a normal jump is slow while a hyper hop is much faster. Air-recovering into a spin is also great as it can be helpful in safely escaping from tech chases. Spin also works in air-to-air best at the same height, not at all if they're lower than you and somewhat if they're higher than you.
Often your opponent thinks they can simply zone out Khan, but as soon as an opening appears in their spam attempts, Khan can nearly teleport into their face. This startles and shocks, causing them to make bad decisions, usually a roll. Khan can punish the opponent then and stick to them like glue for the rest of the round.
Spin can avoid being anti-aired too. You can control the speed by holding either forward or backward. Naturally, you want to go as fast as possible in most cases so you would hold forward, but if you see your opponent preparing an anti-air you can switch to holding backward, the anti-air then misses, you hold forward again and you can punish. The only problem with the spin is its recovery after you hit the ground. If you hit the opponent 3 times while still having quite a long distance to the ground, you'll put yourself at a disadvantage. Thankfully, close to the ground the air spin is plus on hit, even guaranteeing some follow-ups if it hits deep enough.
Khan's backdash is also great. It's a quick leap back, similar to the ones in the KOF series, that covers a decent amount of ground. Note, Khan can cancel the backdash into the spin when his feet are off the ground, lending him a small amount of protection, but the recovery from the spin is far longer than from the dash. Backdashing into his Learning Counter is also a neat trick.
Khan's forward dash is decent. Its speed is serviceable, certainly fast enough to slip d.2A in and go for tick grabs. It can be canceled at any time though it's not instant (you can cancel his dash by pressing back).
