Read a few threads here and there on how the MVC3 guide doesn’t provide an easy to view list on the assists and their properties, so I thought I’d compile a list to do just that, I plan to update this regularly with more info as it becomes available, and with extra info like directions, added effects, what states you’re able to call an assist and so forth. Slightly busy with something atm so the definitions of the assist types aren’t finished yet, special thanks to SRK’s MVC3 guide for making this easier, hopefully this will get stickied 
any grammar errors point them out and any help in general is appreciated.
**When can I use an Assist?
**
- During, standing, walking , dashing , jumping
- During a double/triple jump
- During normal attacks
- During Flight mode
- During Advanced guard
When can’t I use an Assist?
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- During gethit states
- During Special Attacks
- During a super jump
- During a special Move
- If 1 assist is already on screen
- During a HC
- During a DHC
- During blocking
- Flight mode (If SuperJump preceeds it)
Assist Types:
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Wall bounce, Ground bounce, OTG , Soft knockdown, Hard Knockdown, Normal , Trap , Defense , Perk , Low , Overhead
Description of Types
Wall bounce:
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wall bounce attacks may be used as combo extenders, though they can only be used once per combo, if used again it will send the opponent to a soft knockdown state ending the combo.
Ground bounce:
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Ground bounce attacks may be used as combo extenders, though they can only be used once per combo, if used again it will send the opponent to a ‘soft knockdown’ state ending the combo.
OTG:
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OTG short for ‘Off the ground’ are attacks that pick the opponent up from a floored state, primarily used as combo extenders, though it is subject to hitstun deterioration so repeated use in lenghthy combo’s will eventually result your opponent air recovering.
Soft Knockdown:
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During this state your opponent is sent to a floored state, they can be combo’d before reaching the ground however they are immediately allowed to tech roll once grounded, therefore OTG type attacks will miss. It also ignores hitstun deterioration.
Hard Knockdown:
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During this state your opponent is sent to a floored state, they can only be combo’d by attacks with OTG properties, this state has a huge window of oppurtunity, as opponents can’t tech roll once in this state, even slow startup Hypers can combo. This state also ignores hitstun deterioration.
List of OTG’s
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Wesker , B (Samurai Edge)
Sentinel , y (Rocket Punch)
Dormmamu, b (Purification)
Super Skrull, a (Stone Smite)
Taskmaster, y (Aim Master[Verticle Shot])
C.Viper , b (Seismic Gunner)
Hulk , a (Gamma Wave)
Deadpool , b (Katanarama)
Iron Man , y (Smart Bomb)
Dante , b (Crystal)
Viewtiful Joe , y (Shocking Pink)
X-23 , b (Ankle Slice)
Arthur , y (Fire Bottle Toss)
She Hulk , a (Torpedo)
Dr.Doom , b (Hidden Missiles)
List of Low Types
---------------------
Deadpool , a (Quick Work)
Felicia , a (Rolling Buckler)
X-23 , b (Ankle Slice)
She Hulk , a (Torpedo)
Wesker , B (Samurai Edge)
List of Wall bounce’s
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Wesker , a (Ghost Butterfly)
Super Skrull, a (Stone Smite)
Spencer , a (Armor Piercer)
List of Ground bounce’s
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Thor , b (Mighty Smash)
Deadpool , b (Katanarama)
Felicia , y (Cat Spike)
Hagger , y (Steel Pipe)
List of Defense type
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Amaterasu , a (Solar Flare)
Magneto , y (Force Field)
MODOK, a (Barrier)
Hsien Ko , b (Henkyo Ki)
List of Soft knockdowns
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Akuma , a (Tatsumaki Zankuyaku)
Wesker, y (Jaguar kick)
Tronne Bone, a (Bonne Strike)
Super Skrull, b (Orbital Grudge)
Super Skrull, y (Tenderizer)
MODOK, b (Balloon Bomb)
MODOK, y (Psionic Blast)
Hagger , b (Violent Axe)
C.Viper , y (Burning Kick)
Ryu , y (Tatsumaki Senpuukyaku)
Spider Man , b (Web Swing)
Wolverine , b (Berserker Slash)
Magneto , a (EM Disruptor)
Sentinel , y (Rocket Punch)
List of Hard knockdowns
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Chris , a (Punch Combo)
Spencer , a (Wire Grip H. Shot)
She Hulk , b (Clothsline)
List of Normals
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Hagger , a (Double Lariat)
Arthur , a (Heavenly Slash)
Arthur , b (Dagger Toss)
Hulk , b (Gamma Charge Up)
Hulk , y (Gamma Charge Front)
Akuma, a (Gouhadou)
Chris, b (Gunfire)
Hsien Ko , a (Senpu Bu)
Dr.Doom , a (Plasma Beam)
Dr.Doom , b (Hidden Missiles)
Dr.Doom , y (Molecular shield)
She Hulk , (Sommersault Kick)
Dormmamu , a (Darkhole)
Captain America , a (Shield Slash)
Captain America , b (Stars & Stripes)
Captain America , y (Charging Star)
Storm , a (Whirlwind)
Storm , b (Double Typhoon)
Storm , y (Lightning Attack)
Tronne Bone, b (Gustaff Fire)
Tronne Bone, y (Bandit Boulder)
Zero , a (Ryuenjin)
Zero , b (Hadongeki)
Zero , y (Shippuga)
Taskmaster, a (Aim Master[Horizontal Shot])
Taskmaster, b (Aim Master[Parabolic Shot])
Deadpool , y (Trigger Happy)
C.Viper , a (Thunder Knuckle)
Thor , a (Mighty Spark)
Thor , y (Mighty Strike)
Dante , a (Jam Session)
Dante , y (Weasel Shot)
Chunli , a (Kikoken)
Chunli , b (Tenshokyaku)
Chunli , y (Hyakuretsu Kyaku)
Magneto , b (Hyper Gravitation)
Felicia , b (Sand Splash)
Ryu , a (Shoryuken)
Ryu , b (Hadouken)
Iron Man , a (Unibeam)
Iron Man , b (Repulsar Blast)
Morrigan , a (Shadow Blade)
Morrigan , b (Soul Fist)
Wolverine , a (Tornado Claw)
Wolverine , y (Berserker Barrage)
Trish , y (Low Voltage)
Spider Man , a (Web Ball)
Spider Man , y (Spider Sting)
Phoenix , a (TK Shot)
Phoenix , b (TK Overdrive)
Amaterasu , b (Cold star)
Spencer , b (Wire Grip Slant Shot)
Viewtiful Joe , a (Voomerang)
Viewtiful Joe , b (Groovy Upper)
Sentinel , a (Sentinel Force Charge)
Sentinel , b (Sentinel Force Bomb)
Hsien Ko , y (Anki Hon)
X-23 , a (Neck Slice)
X-23 , y (Cresent Scythe)
List of Traps
-----------------------
Trish, a (Hopscotch)
Trish, b (Peekaboo)
Phoenix , y (TK trap)
List of Perks
-----------------------
Amaterasu , y (Bloom)
Morrigan , y (Dark Harmonizer)
List of Overheads
-----------------------
Akuma, y (Hyaki Goju)
C.Viper , y (Burning Kick)
Edit: would also like help categorising the odd 1 or 2 assists like Dormmamu’s Liberation, Spencers , b type or even Hsien Ko’s random Anki Hon, as their positions atm are temporary.