Marvel

• α - Shield Slash - Projectile that hits coming and going
  
• β - Stars & Stripes - Anti-air
  
• γ - Charging Star - Dash attack with shield, multiple hits to extend combos
  

• α - Quick Work - Dash attack that hits low, unblockable setups
  
• β - Katana-Rama! - Vertical slash that might work as anti-air, also hits OTG to extend combos
• γ - Trigger Happy - Projectile at a 45 degree angle
  

• α - Plasma Beam - Horizontal beam projectile
• β - Hidden Missile - Delayed tracking projectile that fires up then falls down, could be useful for pressure with awkward timing
• γ - Molecular Shield - Delayed projectile that eats all other projectiles, multiple hits to extend combos
  

• α - Dark Hole - Multihitting vortex, multiple hits to extend combos
  
• β - Purification - Multihitting pillar, hits OTG to extend combos
  
• γ - Liberation - Does a billion different effects depending on how many charges Dormammu has, charges are expending after a single use
  

• α - Gamma Charge - Dash attack with super armor
  
• β - Gamma Charge (Anti-air) - Upwards dash attack with super armor
  
• γ - Gamma Wave - Multihitting projectile, hits OTG
  

• α - Unibeam - Multihitting beam projectile
  
• β - Repulsor Blast - Shoots short range lasers all around him, anti-air with multiple hits to extend combos
  
• γ - Smart Bomb - Shoots bombs that kinda just fall down and explode
  

• α - 
  
• β -  
• γ -

• α - Barrier - Stationary shield that blocks attacks and projectiles
  
• β - Balloon Bomb - Slow, small, tracking projectile, unclear if assist version will benefit from Analysis Cube
  
• γ - Psionic Blast - Beam projectile, unclear if assist version will benefit from Analysis Cube
  

• α - TK Shot - Horizontal projectile 
  
• β - TK Overdrive - Dash attack, probably best for extending combos
  
• γ - TK Trap - Places a shield in front of her that shoots at a 45 degree angle after a short delay
  

• α - Sentinel Force (Charge) - Three sentinels fly in a horizontal line, good for extending combos
  
• β - Sentinel Force (Bombs) - Three sentinels fly overhead and drop bombs, good for delayed pressure
  
• γ - Rocket Punch - Punches across the screen
  

• α - Torpedo - Dashing low attack for unblockable setups, hits OTG
  
• β - Clothesline - Dashing punch that causes short stun, may help to extend combos
  
• γ - Somersault Kick - Anti-Air flip kick
  

• α - Web Ball - Capture projectile, could be useful for extending combos
  
• β - Spider Sting - Anti-air, unclear if second strike for untechable knockdown will be available in assist form
  
• γ - Web Swing - Single hit swinging attack, probably useless since it won't be good for combos and will leave him extremely vulnerable
  

• α - Whirlwind - Horizontal projectile, multihitting
  
• β - Typhoon - Vertical wind column, hits OTG 
  
• γ - Lightning Strike - Dashing attack
  

• α - 
  
• β -  
• γ -

• α - Aim Master - Horizontal multihitting projectile
  
• β - Aim Master - Multihitting projectile fired at a 45 degree angle
  
• γ - Aim Master - Delayed Multihitting projectile that fires up then falls down
  

• α - Mighty Spark - Horizontal beam projectile, long startup
  
• β - Mighty Smash - Raising attack followed by downward smash, hits OTG
  
• γ - Mighty Strike - Anti-air
  

• α - Tornado Claw - Anti-air
  
• β - Berserker Slash - Single hit dash attack, may cross up depending on range to confuse opponent
  
• γ - Berserker Barrage - Dashing claw attack, multiple hits to extend combos
  

• α - Neck Slice - Leaping slash
  
• β - Ankle Slice - Low dashing slash attack for unblockable setups
  
• γ - Crescent Scythe - Anti-air flip kick
  

Capcom

• α - Gohadoken - Horizontal projectile
  
• β - Tatsumaki Zankukyaku - Horizontal spinning kick, multiple hits to extend combos
  
• γ - Hyakki Gojin - Dive kick, hits OTG and overhead for unblockable setups
  

• α - Solar Flare - Counter attack results in throw
  
• β - Cold Star - Multihitting projectile fired diagonally downward from the air
  
• γ - Bloom - Builds Hyper Combo Gauge ~30%
  

• α - Heavenly Slash - Upward sword slash, may serve as anti-air
  
• β - Dagger Toss - 3 horizontal projectiles
  
• γ - Fire Bottle Toss - Slow traveling fire with short range, multiple hits to extend combos
  

• α - Combination Punch - Series of punches, may be useful for extending combos?
  
• β - Gunfire (SMG) - Multihitting horizontal projectile
  
• γ - Grenade Toss - Grenade that explodes after a short period of time
  

• α - Kikoken - Horizontal projectile
  
• β - Tenshokyaku - Anti-air series of kicks
  
• γ - Hyakuretsukyaku - Repeated stationary kicks, holds enemy in place and is great for extending combos
  

• α - Jam Session - Anti-air, hits very quickly with huge vertical range
  
• β - Crystal - Pillars of ice shoot forward about half-screen, useful for extending combos
  
• γ - Weasel Shot - Multihitting projectile fired diagonally downward from the air
  

• α - Rolling Buckler - Roll into low sliding attack, presumably hits low for unblockable setups
  
• β - Sand Splash - Short range projectile
  
• γ - Cat Spike - Leaping overhead claw attack, unblockable setups and sometimes causes ground bounce(?)
  

• α - 
  
• β -  
• γ -

• α - Senpuu Bu - Swinging attack, hits coming and going
  
• β - Henkyou Ki - Slow, short range, horizontal projectile that reflects other projectiles
  
• γ - Anki Hou - Projectile fired at a 45 degree angle, chance to stun
  

• α - Shadow Blade - Anti-air
  
• β - Soul Fist - Horizontal projectile
  
• γ - Kiss and Throw - Builds Hyper Combo Gauge ~30%
  

• α - Hadoken - Projectile
  
• β - Shoryuken - Anti-air
  
• γ - Tatsumaki Senpukyaku - Worthless
  

• α - Wire Grapple - Horizontal grapple arm, pulls enemies in
  
• β - Wire Grapple (Anti-air) - Grapple arm fired at 45 degree angle, pulls enemies in 
  
• γ - Armor Piercer - Dash punch with wallbounce, interesting combo potential
  

• α - Hopscotch - Places a trap on the ground that fires straight upwards when crossed by an enemy
  
• β - Peekaboo - Places a trap in the air in front of her that explodes for multiple hits when crossed by an enemy, holds in place for combos
  
• γ - Low Voltage - Horizontal projectile
  

• α - Bonne Strike - Dashing drill attack, multiple hits to extend combos
  
• β - Gustaff Fire - Anti-air(?) upward flame attack, mini launcher
  
• γ - Bandit Boulder - Throws a rock
  

• α - 
  
• β -  
• γ -

• α - Thunder Knuckle - Anti-air
  
• β - Seismic Hammer - Point black attack, mini launcher and OTG
  
• γ - Burning Kick - Short range kick that hits overhead for unblockable setups
  

• α - Ghost Butterfly - Thrust punch with wallbounce
  
• *β - Samurai Edge - Short range gun shot that hits low for unblockable setups and OTG*
  
• γ - Jaguar Kick - Double kick with untechable(?) knockdown

• α - Ryuenjin - Anti-air
  
• β - Hadangeki - Projectile that travels along the ground (OTG?) 
  
• γ - Shippugga - Dashing slash, multiple hits to extend combos

the dude that made those videos is from SRK and said today Capcom asked him to take the videos down

So, you'd like some assistance in getting info out about this?  
 
... 
 
I'll see myself out now. 

I can tell you by memory what the best assists for most characters are tho, at least from watching videos and whatnot
 
Wesker: The downward gun assist, because it bounces ppl OTG setting them up for hypers or combos 

Skrull: Easily the tenderizer (100hand slap style move), like his normal tenderizer, it has silly reach and does great dmg (and great chip dmg) 

Dormammu: Dorm has terrible assists, but most say Black hole is the least terrible. the startup on the energy pilar thing is way too long, and his third assist needs to have him with painted hands. 

She Hulk: Easily the sliding punch, because its a low assist, which is both rare and sick 

X-23: the low claw swipe, for the same reasons as she hulk 
 
Pheonix: No idea actually, sorry.
 
Hulk: Hulk has 3 awesome assists, 2 of them have super armor on them (both gamma charges, one forward, the other upward), and the third is a projectile which is always nice. I would tie both gamma charges for best since its really up to what you need really.
 
Chun Li: EASILY the lightning legs assist, Justin Wong was saying its the best assist in the game and its probably true if you've seen the videos. Great dmg, covers a lot of space, holds characters in there for ages giving you time to dash back in
 
Dante: Easily Jam Session for reasons similar to Chun's (jam session being the guitar with purple energy collumm thing)
 
Deadpool: His upward guns assist seems to be the best.
 
Morrigan: The dragonpunch (it goes horizontally as much as upward, its sick) assist is the best, but the battery one is amazing for different purposes.
 
Felicia: Like Pheonix, I have no idea.
 
Spencer: His grapple assists that pull chars in (one in front, other in the air) seem to be the best if you know how to use them, I like the straight punch one tho because it bounces off the wall
 
Arthur: EASILY the fire bottle / torch, especially in gold armor
 
Taskmaster: No idea
 
Akuma: No Idea
 
Ryu: Probably the dragonpunch one, even if its not as good as Morrigan's. Fireball is always useful tho.
 
Captain America: Shield Slash since it hits on the way back
 
Ironman: Still the Repulsor Blast
 
Storm: TYPHOON!
 
Magneto: Distruptor for me, some might say hyper grab assist. the counter one is terrible it seems.
 
Sentinel: I love air raid to catch incoming tags, but the straight drones assist still seems beastly too. Its a toss up imo.
 
Hsien-Ko: Probably her pendulum assist, whatever that move is called.
 
C.Viper: Easily the burn kick, since its an overhead
 
Spider Man: His assists seem lackluster, web ball is probably the best, at least its the most annoying.
 
Wolverine: Berserker Barrage still I think
 
Chris: No idea
 
Modok: Psyonik blast seems to be the most useful
 
Trish: I love her traps so ill say the trap assist, but her projectile one seems pretty fast.
 
Zero: Dunno actually, I always see him on point :(
 
Tron: The drill
 
Thor: He seems to have terrible assists, Mighty Smash is probably the best since the start up on his projectile is terrible
 
Ammy: EASILY the cold shot assist, its also one of the best in the game
 
V.Joe: Dunno, cant think of any besides the bomb assist, which seems terrible
 
Haggar: No idea
 
Doom: Still the rocks

Gong assist for Hsien'Ko will be great for battling fireball characters.
 
All three Taskmaster assists will be his Aim Master special move fired either horizontally, diagonally, or vertically.
 
I'm still trying to decide on the best AA assist to work with my Taskmaster/Trish team, I've been leaning toward Hulk for a while now and I think I've finally been pushed over the edge since I like the idea of a Rushdown/Keepaway/HULK team.

Marvel

• α - Shield Slash - Projectile that hits coming and going
  
• β - Stars & Stripes - Anti-air
  
• γ - Charging Star - Dash attack with shield, multiple hits to extend combos
  

• α - Quick Work - Dash attack that hits low, unblockable setups
  
• β - Katana-Rama! - Vertical slash that might work as anti-air, also hits OTG to extend combos
• γ - Trigger Happy - Projectile at a 45 degree angle
  

• α - Plasma Beam - Horizontal beam projectile
• β - Hidden Missile - Delayed tracking projectile that fires up then falls down, could be useful for pressure with awkward timing
• γ - Molecular Shield - Delayed projectile that eats all other projectiles, multiple hits to extend combos
  

• α - Dark Hole - Multihitting vortex, multiple hits to extend combos
  
• β - Purification - Multihitting pillar, hits OTG to extend combos
  
• γ - Liberation - Does a billion different effects depending on how many charges Dormammu has, charges are expending after a single use
  

• α - Gamma Charge - Dash attack with super armor
  
• β - Gamma Charge (Anti-air) - Upwards dash attack with super armor
  
• γ - Gamma Wave - Multihitting projectile, hits OTG
  

• α - Unibeam - Multihitting beam projectile
  
• β - Repulsor Blast - Shoots short range lasers all around him, anti-air with multiple hits to extend combos
  
• γ - Smart Bomb - Shoots bombs that kinda just fall down and explode
  

• α -
  
• β -  
• γ -

• α - Barrier - Stationary shield that blocks attacks and projectiles
  
• β - Balloon Bomb - Slow, small, tracking projectile, unclear if assist version will benefit from Analysis Cube
  
• γ - Psionic Blast - Beam projectile, unclear if assist version will benefit from Analysis Cube
  

• α - TK Shot - Horizontal projectile
  
• β - TK Overdrive - Dash attack, probably best for extending combos
  
• γ - TK Trap - Places a shield in front of her that shoots at a 45 degree angle after a short delay
  

• α - Sentinel Force (Charge) - Three sentinels fly in a horizontal line, good for extending combos
  
• β - Sentinel Force (Bombs) - Three sentinels fly overhead and drop bombs, good for delayed pressure
  
• γ - Rocket Punch - Punches across the screen
  

• α - Torpedo - Dashing low attack for unblockable setups, hits OTG
  
• β - Clothesline - Dashing punch that causes short stun, may help to extend combos
  
• γ - Somersault Kick - Anti-Air flip kick
  

• α - Web Ball - Capture projectile, could be useful for extending combos
  
• β - Spider Sting - Anti-air, unclear if second strike for untechable knockdown will be available in assist form
  
• γ - Web Swing - Single hit swinging attack, probably useless since it won't be good for combos and will leave him extremely vulnerable
  

• α - Whirlwind - Horizontal projectile, multihitting
  
• β - Typhoon - Vertical wind column, hits OTG
  
• γ - Lightning Strike - Dashing attack
  

• α -
  
• β -  
• γ -

• α - Aim Master - Horizontal multihitting projectile
  
• β - Aim Master - Multihitting projectile fired at a 45 degree angle
  
• γ - Aim Master - Delayed Multihitting projectile that fires up then falls down
  

• α - Mighty Spark - Horizontal beam projectile, long startup
  
• β - Mighty Smash - Raising attack followed by downward smash, hits OTG
  
• γ - Mighty Strike - Anti-air
  

• α - Tornado Claw - Anti-air
  
• β - Berserker Slash - Single hit dash attack, may cross up depending on range to confuse opponent
  
• γ - Berserker Barrage - Dashing claw attack, multiple hits to extend combos
  

• α - Neck Slice - Leaping slash
  
• β - Ankle Slice - Low dashing slash attack for unblockable setups
  
• γ - Crescent Scythe - Anti-air flip kick
  

Capcom

• α - Gohadoken - Horizontal projectile
  
• β - Tatsumaki Zankukyaku - Horizontal spinning kick, multiple hits to extend combos
  
• γ - Hyakki Gojin - Dive kick, hits OTG and overhead for unblockable setups
  

• α - Solar Flare - Counter attack results in throw
  
• β - Cold Star - Multihitting projectile fired diagonally downward from the air
  
• γ - Bloom - Builds Hyper Combo Gauge ~30%
  

• α - Heavenly Slash - Upward sword slash, may serve as anti-air
  
• β - Dagger Toss - 3 horizontal projectiles
  
• γ - Fire Bottle Toss - Slow traveling fire with short range, multiple hits to extend combos
  

• α - Combination Punch - Series of punches, may be useful for extending combos?
  
• β - Gunfire (SMG) - Multihitting horizontal projectile
  
• γ - Grenade Toss - Grenade that explodes after a short period of time
  

• α - Kikoken - Horizontal projectile
  
• β - Tenshokyaku - Anti-air series of kicks
  
• γ - Hyakuretsukyaku - Repeated stationary kicks, holds enemy in place and is great for extending combos
  

• α - Jam Session - Anti-air, hits very quickly with huge vertical range
  
• β - Crystal - Pillars of ice shoot forward about half-screen, useful for extending combos
  
• γ - Weasel Shot - Multihitting projectile fired diagonally downward from the air
  

• α - Rolling Buckler - Roll into low sliding attack, presumably hits low for unblockable setups
  
• β - Sand Splash - Short range projectile
  
• γ - Cat Spike - Leaping overhead claw attack, unblockable setups and sometimes causes ground bounce(?)
  

• α -
  
• β -  
• γ -

• α - Senpuu Bu - Swinging attack, hits coming and going
  
• β - Henkyou Ki - Slow, short range, horizontal projectile that reflects other projectiles
  
• γ - Anki Hou - Projectile fired at a 45 degree angle, chance to stun
  

• α - Shadow Blade - Anti-air
  
• β - Soul Fist - Horizontal projectile
  
• γ - Kiss and Throw - Builds Hyper Combo Gauge ~30%
  

• α - Hadoken - Projectile
  
• β - Shoryuken - Anti-air
  
• γ - Tatsumaki Senpukyaku - Worthless
  

• α - Wire Grapple - Horizontal grapple arm, pulls enemies in
  
• β - Wire Grapple (Anti-air) - Grapple arm fired at 45 degree angle, pulls enemies in
  
• γ - Armor Piercer - Dash punch with wallbounce, interesting combo potential
  

• α - Hopscotch - Places a trap on the ground that fires straight upwards when crossed by an enemy
  
• β - Peekaboo - Places a trap in the air in front of her that explodes for multiple hits when crossed by an enemy, holds in place for combos
  
• γ - Low Voltage - Horizontal projectile
  

• α - Bonne Strike - Dashing drill attack, multiple hits to extend combos
  
• β - Gustaff Fire - Anti-air(?) upward flame attack, mini launcher
  
• γ - Bandit Boulder - Throws a rock
  

• α -
  
• β -  
• γ -

• α - Thunder Knuckle - Anti-air
  
• β - Seismic Hammer - Point black attack, mini launcher and OTG
  
• γ - Burning Kick - Short range kick that hits overhead for unblockable setups
  

• α - Ghost Butterfly - Thrust punch with wallbounce
  
• β - Samurai Edge - Short range gun shot that hits low for unblockable setups and OTG
  
• γ - Jaguar Kick - Double kick with untechable(?) knockdown
  

• α - Ryuenjin - Anti-air
  
• β - Hadangeki - Projectile that travels along the ground (OTG?)
  
• γ - Shippugga - Dashing slash, multiple hits to extend combos
  

ill help you clear some of those ?s 

you cant have the giant aegis reflector as an assit, its just the normal one, no matter how many anallize cubes you have.
viper´s sismo IS otg 
haggar does have a lariat assist, and it does take a bit of his life 
only the last hit of felicia´s roll assist hits low, the rest are high 
akuma´s dive kick is also an overhead

she hulk´s torpedo does hit otg (just like her regular torpedo when shes on point)

i dont believe sent´s rocket punch assist is OTG, since it goes straight and u cant control it, unlike the point one which you can shoot down and IS otg

hulk´s gamma wave assist is otg

In the process of editing the first post. It's a pain because their isn't any solid info yet, and what there is happens to be spread all over the internets. I'll finish it up today. 

 Joe:

A          Voomerang                Shot                 >

B          Groovy Uppercut       Direct               >^

Y          Bomb Toss                 Shot                 >V

Haggar:

A          Double Lariat                         Direct               Instant

B          Violent Axe                Direct               >

Y          Steel Pipe                   Direct               >

Skrull:

A          Stone Smite               Direct               >

B          Orbital Grudge           Direct               >

Y          Tenderizer                  Direct               >^

Magneto:

A          Disruptor                     Shot                 >          

B          Hyper Gravitation      Shot                 >

Y          Force Field                 Extra                Instant