Light Kick
	Strong Kick
	Heat Mode
	Light Punch
	Strong Punch
	Not used
	Taunt

The decriptions for each move are based on my personal experience of KOF. As I use to play a lot with Clark in local arcades against strong human opponents, I will try to give you some hints & advices in order to use this character the way he is in KOF. I think this can also apply to M.U.G.E.N (even if some things can't be reproduced since those are mind games based on command guessing ...)
If you need more informations on how to use Clark, combos, strategies & other KOF-related mind games, I would recommend you to check out the FAQs like on GameFaqs for example. I remember there is a good Clark FAQ by Hebretto there, go and read it.

Emergency Evasion (Roll) :
This is the classic roll used since KOF'96 with KOF'98 standards. Note that you are vulnerable to any throw while rolling so don't perform it too much, especially against grapplers.

Knockdown Attack :
This move is really slow to pull out but has a good air range while close to opponent. I don't recommend using it since Clark has better basic moves than this one.

Guard Cancel Evasion : while guarding a hit
Very useful if you know your opponent will perform a combo you know about which last hit has a slow recovery time (roll before opponent executes last hit[s] of his combo). Another function of this move is to avoid block damage, like while guarding K9999's SDM for example.
Guard Cancel Attack : while guarding a hit
This is a useful tool when you want to get your opponent fly away, in order to escape from a combo, from block damage / guard crush or from being cornered. Use with caution though : if opponent lands a late air hit and if you perform the Guard Cancel Attack, you will miss opponent 95 % of the time (because p2 will have enough time to block the G.C.A).

Guard Cancel Attack Evasion : during any basic move
This is a feature introduced in KOF 2002 in order to punish people who rely too much on the Guard Cancel Attack.
Indeed, perform the Guard Cancel Attack Evasion during any basic move if you think your opponent will try to G.C.A you. In the case of a success, you will get up while opponent is still in his G.C.A motion, and here you go for a damaging punishment (let's say close strong punch, Stomping, Mount Tackle, Clark Lift).

Slamming German : or + (while close to opponent)
Nothing much to say about this throw except the fact that there's a huge recovery time at the end, so don't perform it while in corner because if opponent recovers on ground from Slamming German, you will be punished.

Fisherman Buster : or + (while close to opponent)
This throw inverses player sides.

Death Lake Drive : any direction (except ,,) + or
An important piece of Clark strategy. Death Lake Drive is very useful if you guess your opponent will jump to avoid Super Argentina Backbreaker or Frankensteiner. Use it as much as possible in order to keep your pressure and to confuse your opponent.

Super Argentina Backbreaker : or
The main strength of Clark. This throw has very good priority and will grab most of the time, even if your opponent looks a bit away from you (close strong punch also has a good range). Can be used while running, after a small jump, after Guard Cancel Attack / Guard Cancel Attack Evasion ..... Note that light & fast hits can prevent Clark from grabbing (Benimaru's crouching light kick for example) and that this year, Clark has a somewhat noticeable recovery time if he misses the throw (that was not the case in KOF'99 & KOF'01 ... fortunately it's not the horrible recovery time of KOF 2000).
50 % of Clark strategy is based on this move, along with Death Lake Drive. The remaining 50 % include most basic moves and Frankensteiner. I will not explain why, check GameFaqs to know. Flash Elbow is available to finish off opponent.

Frankensteiner : or
Another piece of Clark strategy. This throw is invincible to any attack except throws & fireballs. Frankensteiner is useful to grab landing opponents /  waking up opponents, to avoid being hit by light moves [in the case opponent thinks you will try to grab him with Super Argentina Backbreaker ... a bit more advanced mind game heh] or simply as an alternative to confuse opponent. A version is faster than B version, but both have a huge recovery time if missed. Use with caution. Flash Elbow available as a followup.

Napalm Stretch : or
This is an air throw. Clark will jump and try to grab a jumping opponent. Use this move only in the case you know your opponent will perform a neutral jump (i.e jump without attack) because this throw has very low priority compared to Death Lake Drive and you can be hit very easily. I recommend using it exclusively as a followup of Gatling. You can land a Flash Elbow as a followup.

Mount Tackle :   or
This is a throw where Clark runs then aims opponent while running. This move has 3 followups in KOF, I added a 4th one in the M.U.G.E.N. conversion which is a DM/SDM set, the Twisted Wrestle. Mount Tackle can be used to grab landing opponents, but the main feature of this move in KOF'02 is that it is a followup of the Stomping (forward + light kick). You can already spot here the most damaging normal combo of Clark : close strong punch (1 hit), Stomping, Mount Tackle, Mount Tackle followup. I strongly recommend you to use it to perform this combo and only in that case because this move has a big recovery time so don't use it unless you know what you're doing.
In KOF'02, you can escape from the Mount Tackle, but not in '99 - 2000 - 2001. The Mount Tackle I added is the '99 - 2K1 style one. Sorry people but since not all M.U.G.E.N. characters use standard animations for throw escaping ... =|
Mount Tackle followups must be performed at the end of the move, when Clark holds opponent on ground and is about to stop sliding.

Clark Lift :
The first Mount Tackle followup. Clark will hold opponent and slam him hard on ground.

Rolling Cradle : or
The second Mount Tackle followup. Clark will crush opponent by pressing him on ground in a rolling motion.

Super Lift D.D.T :
The third Mount Tackle followup. Clark will simply slam opponent on ground in a falling motion. You can finish with a Flash Elbow.

Shining Wizard : or
The new KOF'02 move which has replaced Gatling. If you are a wrestling fan, you already know what this move is, but for people who don't know about Shining Wizard, here's a quick explanation. Clark is supposed to land the first foot on a crouching opponent's knee, then hits him hard with his other leg, using his knee to hit the head. Well at least that's the description I got off some random guy.
This move will only hit if opponent is crouching (for the reasons explained above). Can be useful if opponent is turtling / thinking you will try to land a crouching strong kick on him. I personally like this move but Gatling was the only move which had block damage :'(

Gatling : (hold for a second), or
SUPER ATTACK CANCEL AVAILABLE ON 1ST & 2ND HITS
This move is kinda cool to perform and to use since it will connect from a close strong punch or a crouching light punch. X version is a 2 hit move, while Y version has 3 hits. Gatling can be linked with the Napalm Stretch.
Don't use it alone, as it is a somewhat weak move (weird priority).

Flash Elbow : or
A followup-only move. Can be performed at the end of Super Argentina Backbreaker, Frankensteiner, Napalm Stretch and Super Lift D.D.T. Always perform it if available (if one of the named moves succeeded). Note that you can delay a bit the move, but this can have bad effects (Clark won't perform it if launched too late during Super Argentina Backbreaker final frames, he won't hit if launched too late during Frankensteiner last frames ...). Be careful : landing a Flash Elbow on a cornered opponent often results in a miss.
The fact that you have to delay it is a little issue in KOF where some opponents won't get hit by an early Flash Elbow as a Frankensteiner followup. You can try this against K9999 in KOF'01 or against Iori Yagami in KOF'02, you will see what I'm talking about. But that's not the problem, the M.U.G.E.N version will hit.
 

Stomping : +
Can be useful to press opponent after a close strong punch, this will also avoid some slides & some sweep kicks. But the main use of this move is a link from the close strong punch (because you can launch Mount Tackle after Stomping).

Counter - High : "USER PREFERENCES"
This move will counter any air or standing attack, may it be normal, super or attack except hyper attacks, throws & fireballs. Therefore the weak point of this move is the leg section : any attack aiming this part of Clark's body will result in a success. Fast to pull out but stays quite long, so be careful.

Counter - Low : "USER PREFERENCES"
It doesn't look efficient but it will counter any low normal or special attack except hyper attacks, throws & fireballs, and only crouching ones, i.e all air/standing attacks will hit Clark. Fast to pull out but stays quite long, so be careful.

 Shoulder Break :   or "USER PREFERENCES"
A sprite edit that enables Clark to receive a new move ! It is a sliding shoulder attacks that deals niec damage and allows user to chain with any other special move and/or DM/SDM. It has nice priority and decent recovery.

Ultra Argentina Backbreaker : or
A tuned-up version of the Super Argentina Backbreaker. Finisher is a Death Valley Bomb.

Running Three : or
Clark will run towards opponent and will try to grab him. In case of success, he will show the direction where he will slam opponent.

Twisted Wrestle : or "USER PREFERENCES"
The new 4th Mount Tackle Followup. It is an original wrestling style DM I invented using all existing sprites I could use. The result got better than I expected, and seeing the positive feedback I got from it, I decided to keep it. It now has a new finisher which is the Northern Light Bomb (wrestling move), directly edited from Ralf.

 Special Gatling Attack :   or
New KOF XI DM. It is basically a 5 hit Gatling attack.

Ultra Argentina Backbreaker :
A tuned-up version of the Ultra Argentina Backbreaker DM. Finisher is randomly KOF'02 or KOF'03 style (Clark Spark)

Running Three :
Clark will run towards opponent and will try to grab him. If succeeded, he will slam opponent 3 times.

Twisted Wrestle : "USER PREFERENCES"
The new 4th Mount Tackle Followup. It is an original wrestling style SDM I invented using all existing sprites I could use. The result got better than I expected, and seeing the positive feedback I got from it, I decided to keep it. The SDM version receives 3 finishers, depending of the distance : Ground Zero (a.k.a Shining Drop), Horse Mounted Ralf Kick & Reversed Frankensteiner.


V-Slasher : "USER PREFERENCES"
A new SDM for Clark. He will basically summon Leona in order to perform her V-Slasher SDM. Note that Clark can't move for a long time, this is to keep balance since Leona is invincible to anything during her SDM attempt.

Umanori Galactica Phantom : "USER PREFERENCES"
Ralf enters in order to perform his Umanori Galactica Phantom. Note that Clark can't juggle opponent on ascending phase. 

Mega Running Spark :
This is similar to the Running Three SDM with the following differences :
- Clark presses opponent on wall twice
- finisher is a Pile Driver
- damage is importantV-Slasher SDM, Umanori Galactica Phantom HSDM & more ...

Clark has few combos. That's pretty normal since he is a grappler-style character, who relies a lot on his throws.
You can find Them by yourself, by checking out FAQs, the CMD file, watching the AI, the comments of this page ...