This achievement can be done in Practice Mode. If you don't think you'll be overwhelmed, you can go for 'Superhuman' and 'Metahuman' at the same time.
Go to practice mode and choose a character. Work your way through each character in order, to help you keep track.
Once in game, go to PRACTICE OPTIONS and set METER GAIN to REFILL. Next, go to MOVES LIST and scroll over to SPECIAL MOVES. Observe which specials have a Meter Burn variation (it should say Meter Burn underneath it) and tag these using Y.
Meter Burn specials are done by holding the Meter Burn button (RT by default) immediately after inputting a special move. You'll know you've done a Meter Burn special correctly if you see a section of your super meter used (this is why we use REFILL instead of FULL meter gain).
Some meter specials will only activate under certain conditions. There are quite a few meter burns that only activate on hit, meaning the attack has to hit your opponent before the meter burn variation can be activated.
There are also some meter specials that will require you to record the AI doing things like duck, jump, or attack. This is because some specials only hit crouching characters, airborne characters, or are counters which require being attacked to activate. If a move isn't connecting, use the description of the special move in the special moves list to determine what you need to do.
Once you've done all the meter burn specials on a character, return to player select and repeat with the rest of the cast. Once you've done every meter burn special, the achievement will unlock once you leave practice mode.If it didn’t unlock for you, these are the things that are easily missed to check for first:
Raven’s Demon Stance:
Her demon stance character power has a very limited amount of time before you go back to normal. Keep an eye on this while performing her demon stance specials, and wait for it to recharge after it runs out.
Raven’s Empty Void Meter Burn:
Empty void is a projectile counter. You need to record the practice dummy firing a projectile. Then you need to perform empty void to absorb it and meter burn it. Done correctly, it will fire a projectile back at your opponent.
Shazam’s Achilles’ Clutch:
This move only hits ducking opponents. The throw has to be performed in order for the meter burn version to come out. Set the dummy to duck.
Lex Luthor’s Gravity Mines:
Aim for the feet. It disappears if it hits the opponents body. Time the meter burn version with when the mine activates and hits the opponent.
Killer Frost’s Frostbite:
This is a counter move. The meter burn version requires you to get hit to activate. Record the dummy doing attacks.
Deathstroke’s Low Sword Spin:
His sword spin has two meter burn variations. The low spin version can be easily overlooked. Hold down after performing the meter burn sword spin normally.
Doomsday’s Air Snatch:
This move requires an airbourne opponent. Set the dummy to jump to do the meter burn variation.
If you think there's something you may have overlooked, or not sure if you're doing a move right, here is a series of videos for every special move, meter burn, and super:http://www.youtube.com/playlist?list=PLSvi5kfsxQY0XTpcSVKs_v...