Differences from MK3
Ermac did not appear in MK3
Move List
Basic Moves
The Male Ninjas have excellent basic moves, good height and range on everything in relation to their sprite proportions, their roundhouse is extra wicked and can connect in almost any situation. The only thing that can be weird about them is their aaHPs. Sometimes they tend to miss in situations where you wouldn't expect them to and this is due to kara canceling with run to speed the last hit up, in this situation, often you can do aaHP,LP and it'll work, with slightly less damage, otherwise, always take an extra small step in before doing aaHPs.
Special Moves
Telekinetic Slam
B, D, B, HK
5.5% Damage
The Telekinetic Slam is one of the most broken and unique moves in the game, however you need to learn how to max out the combos off it. Its properties are a little unorthodox, as it does damage, but does not count as a hit in a combo (unless you hit them before the first bounce in which it doesn't do damage). It does not activate damage protection and has a limit of 4 hits before it is locked, and this means 2 usages per combo are about the norm. There are ways to stretch it to 3 uses but they have to be absolutely perfectly time with no room for error so it's not worth getting into because you really can't get any more damage than normal this way conventionally. Your standard set ups are going to be either hit, TKS, hit, hit, hit, TKS -or- TKS, hit, hit, hit, hit, TKS, etc. Make sure to try and labor the 3 hit succession just a bit to elapse the time limit inbetween uses, which isn't noticable usually. Good set ups for the TKS are anti air HPs if someone JKs early, this the perfect time to aaHP and cancel to a TKS. From here a guaranteed 78% damage combo is possible on almost every character, more difficult on some than others, but on characters like Shang you need to be slightly more rigid with the timing and max out about 75%, otherwise it's not worth trying the extra hits, and on a lot of characters 82% standard counter from a standing aaHP is possible. Remember that the TKS doesn't count as part of a combo it also doesn't add to the damage for some reason, so for every TKS you use in a combo, add 5.5% to the end damage read outand 3% in DPed combos, generally two should always be used in a combo so that's 11%. In the corner you can set up a TKS combo off an aaRH easily. Remember to run cancel all your jabs during juggle combos to allow more time for extra jabs and JKs. It is possible to glitch cancel (on the frame of contact) up to 5 hits before a TKS, but it is not recommended
Teleport Punch
D, B, HP
9% Damage
The Teleport Punch is a great move if used for escaping and overall positioning and manueverability. If you use it too much players will see your patterns and counter by getting in the way of it and blocking. If you are experienced enough with the placement and timing you should be able to teleport almost anytime it is available (it has a small time limit between usages) and not get punished. Use if when you are getting up to escape run jabs, HKs or knee starting combos. Ermac turns invisible when he does the teleport punch and is still actually on the screen moving until he lands or shows up on the other side of the screen. If you are air thrown or Bike Kicked, for example, before you leave the screen Ermac will stay invisible until he is hit by another move. Take advantage of this, an invisible Ermac is an even dealier Ermac. Try only to teleport when you have 2/3 of the screen behind you or at least a total of 2/3 screen distance between you and your opponent in some manner. This would mean, you can have half a screen behind you and your opponent is standing right next to you, you'll wind up landing about sweep distance away behind them. It is best to try and get the placement down to land right next to them even if they are blocking, this sets up free throw potential and/or rush down. Watch out for counter sweeps, LKs, HKs or uppercuts if you rush in immediately. Utilize the teleport punch as a combo extender but try not to actually hit them with it as it activates damage protection. Its limit is 4 hits before it is locked, has a small window of time limit recharge and you can stretch it out to 2 uses per combo if done right. A good way to start a DPed juggle combo would be to aaRH an incoming JK and hit a teleport punch on the other side before they land. After this do a TKS, wait, RH, again, teleport punch, TKS again, to standard finish of choice. Do not use the teleport punch as a safe guard chip hit when someone is on danger because it only does about 2% chip damage and danger can mean the person has 4% life left. It is common to see people lose matches they should have won because of this. In order to connect his teleport punch on characters like Shang Tsung, Liu Kang, female ninjas, Robots Ninjas, and Sheeva in mid screen standard combo situations, after his HK, LP pop up, jump forward and wait until he starts coming down on the flip to JK, then instantly cancel to the teleport punch. This makes him line up better with them. You can also glitch cancel the teleport punch if you want to get fancy.
Green Spark
D, B, LP
12% Damage
The Green Spark is a standard, slow starting fireball and is only good to use as a combo terminator. In most cases if you realize you're not going to be able to get 3 aaHPs at the end of a juggle (it's noticable on how the aaHPs connect after the second TKS) you can subsitute aaHP,HP, aaLP, fireball and that will usually connect and is compenstable upon reaction. There are no tactical uses for his fireball. There is never a time when a fireball can be used as a last resort on a jumping back opponent with him when a teleport punch would be better and more of a guarantee. In general the fireball leaves him too open because it takes him forever to recover, you can jump over it easily, and he stays in one position.
Finisher Moves
Fatality 1
D, U, D, D, D, BL (Sweep) (Hold Block)
Ermac raises his hand, his victim is then slammed multiple times and eventually explodes to pieces.
Fatality 2
RUN, BL, RUN, RUN, HK (Next to)
Ermac knocks his opponents head off just like Cage in MK2.
Babality
D, B, B, F, HP ? (No Block in Winning Round) (Past Sweep)
Mercy
Hold RUN, Wait 1 Second, D, D, Release RUN (Round 3) (Past Sweep)
Stage Fatal
RUN, RUN, RUN, RUN, LK (Next to)
Strategy
As Ermac
Ermac is a high tier top 10 character, he is ranked 8th but in the right hands can be considered top 3 as his combo/juggle ability is unparalleled in terms of average damage per combo coupled with the relative ease. He is played very much like Human Smoke, except without air throw tactics. His average combo ability is around the 50% or more on anyone at anytime. I will list many specific character combos in his juggle section. What you are going to try and do with him out of the ordinary teleport methods is anti air HP counters on jump ins and what you can do with that is cancel the HP with block so you cannot be accidentally hit and if you do hit your HP you still have plenty of time to cancel with a Telekinetic Slam (TKS). Watch out against Kano and Nightwolf JKs because they tend to still over prioritize aaHPs if you don't time it right, instead aaRH them. Against agressive players you can throw out a TKS sometimes after a blocked auto combo, and they will get snagged by it. Against jumpy or overly aggressive players you can stick in a TKS after an aaHK if you so choose to use it over the aaHP, and often times it will get them on their wake up. Don't over use it. Run and knee jab mix ups, teleporting away from and landing next to are a must but watch out because players can scout the teleports and position themselves to get in the way of what you might think is a safe teleport, punishing you for it. His walking speed is slower than Human Smoke's so multi jab juggles need to be timed more rigidly. The only combo you should ever use midscreen is HK, LP when rushing down, and off starters.
VS Ermac
Combos
Ermac can relaunch all characters in the game like Kano and Human Smoke. Some characters are more difficult than others, in order to best line him up, you should do his pop up, pause slightly before jumping forward, and punch at the last possible moment. 
Basic Juggles that work on everyone: 
1. HK, LP, JK, teleport punch, TKS, aaHP,HP, fireball 7 hits about 42% 
2. (for a punisher) aaHP,HP, JK, teleport punch, TKS, aaHP,HP, fireball 7 hits about 53% 
3. punch starter, HK, LP, aaHP, TKS, aaHP,HP, fireball 7 hits about 43% 
4. (for a punisher) aaHP, TKS, aaHP,HP, aaHP, TKS, aaHP,HP, aaHP, fireball 8 hits 69% 
Advanced Juggles: 
These are maxed out combo situations that work faithfully with little risk of failure on all characters except Shang, Sonya, Liu Kang, and Sheeva. Adjustments are required for the slightly lesser damage combos on the specific opponents mentioned with usage of one less HP, or a fireball instead of a JK at the end, downgrading the combos by about 15% 
1. HK, LP, JK, teleport punch, TKS, aaHPHP, aaHP, JK 8 hits about 47% on Sub-zero, Jax, Stryker, and Male Ninjas, you can walk in after the HK, LP, and do a RH, then teleport punch, perform the TKS motion backwards because the teleport punch usually juggles behind him, for 48% 
2. punch starter, HK, LP, JK, TKS, aaHP,HP, aaHP, JK 8 hits 52% 
3. (for a punisher) aaHP,HP, JK, teleport punch, TKS, aaHP,HP, aaHP, JK 8 hits 58% 
4. aaRH, teleport punch, TKS, aaRH, teleport punch, TKS, aaHP,HP, aaHP, JK 8 hits 62% 
5. (for a punisher or counter to a jump in attack) aaHP, TKS, aaHP,HP, JK, TKS, aaHP,HP, aaHP, JK 8 hits 82% 
6. (Opponent at Midscreen) TKS, aaHP,HP, teleport punch (miss), aaHP, JK, TKS, aaHP,HP, aaHP, JK 8 hits 82% 
7. try and stick in an otg (off the ground) HK LP after his TKS for some neat looking juggles HK, LP, JK, teleport punch, TKS, HK, LP, aaHP, fireball 8 hits 46% 
Advanced Corner Juggles (watered down): 
1. HK, LP, JK, RH, (or aaHP), TKS, aaHPHP, JK, RH, HK, (or LK) 9 hits 64% (58%) 
2. punch starter, HK, LP, RH (or aaHP), TKS, aaHP,HP, JK, RH, HK (or LK)9 hits 66% (60%) 
Corner 100% juggles: 
1. TKS, aaHP,HP, JK, aaHP, TKS, aaHP,HP, JK, RH, LK (works on just about everyone and is good if someone does a projectile in the corner and Ermac is about half screen away) 
2. aaHP, TKS, aaHP,HP, RH, TKS, aaHP,HP, JK, RH, LK 
3. aaRH, TKS, aaHP,HP, aaHP, TKS, aaHP,HP, JK, RH, LK 
4. suJK, TKS, aaHP,HP, RH, TKS, aaHP,HP, JK, RH, LK