Copy pasting your Doom sheet and modifying it, this is my opinion and other Vipers may or may not agree.
[FONT=Helvetica]Reliance on assists on point without XF = Assists cover bad match ups, enhance match ups she already wins.[/FONT] Moderate (Best place for her to be)
[FONT=Helvetica]Reliance on assists with XF2 = Low, faster seismo start up and stupid mix ups make her need for assists lower in XF2, mainly useful for once she’s in, in this state. XF 2 can be avoided as 236C cannot be feinted in X-factor 2, thus forcing separate combos. If you learn different combos for it however all is well.[/FONT]
[FONT=Helvetica]XF3/Anchor abilities = As an anchor she’s incredibly fast and thus both hard to control and hard to block. Her ability to chip in this mode is very high provided you have the execution to deal with advance guarding and she builds gauge while chipping instead of using it. She can kill every character off of any throw at any height, any hit at any height, and in the process can force the next victim to fall in, in the corner.[/FONT]
General preferred assists breakdown:
Spencer (Slant shot)
Magneto (EM Disruptor)
Akuma (Tatsumaki zanku kyakku)
Taskmaster (Horizontal aim master or Vertical aim master)
Dante (Jam Session preferred though all 3 are useful for her)
Amaterasu (Cold Star)
Doom (Hidden Missiles Or Plasma Beam)
Storm (Horizontal Whirlwind)
Sentinel (Charge Drones)
Felicia (Rolling Bucklet)
Dormammu (Dark Hole)
Zero (Hadangeki once in Sougenmu)
MODOK (Floating bomb or barrier)
Hsien-Ko (Senpu-bu once in Rimoukon mode)
I’ve likely missed a few but I’ll edit this post when I remember them
[FONT=Helvetica]Strong assists for lockdown/pressure[/FONT]
Dante (Jam session): is exceptional for her lock down, pressure, and space control games, it alone single-handedly reverses a lot of her bad match ups and is probably the most vital assist to have for Viper IMO. She can get unblockables, mix up, and combos off of this and it forces a lot of mistakes from people coming in if they know the unblockable is coming. Good combo ender as well.
Dante (Crystal): although this sadly means not having Jam Session, Viper can get a lot done with this as it extends her combos for exceptionally high damage, letting her link things after light and medium thunder knuckles without much difficulty at a very hit confirmable time. Controls an awful lot of space making 623B + Crystal assist a close to impenetrable wall from the ground, forcing enemies to the dangerous skies.
Akuma (Tatsumaki Zanku Kyakku): is universally a good assist, but Viper gets higher damage than most off of it on hit and unlike everyone else can use it for unblockables in the corner. It also assists in her zoning game since with it eating projectiles and her seismic hammer eating projectiles they blaze through a lot of otherwise solid zoning tools.
Amaterasu (Cold Star): areat for mix up, pressure, and unblockables. provides guarenteed kills on characters who lack air mobility, good combo ender as well.
Dr. Doom (Hidden Missiles): if Viper corners an enemy and has this assist it’s their job to never let her summon it as she gets a very dangerous unblockable set up. Along with this it also supplements her zoning game, especially the air component.
Dormammu (Dark Hole): she gets focus unblockables off of this and like Akuma it eats projectiles and gives awhile to hit confirm. Awkward static spacing makes it less useful for her than tatsu assist, but still decent.
Sentinel (Charge Drones): like all highly mobile characters with a zoning tool she can use Drones for anything from mix up, to zoning, to a way to get in more easily. With burn kicks and burn kick feints she has a very confusing left right game that’s visually disorienting. If this connects in the corner a stupid amount of seismic hammers can be fired off for chip.
Chun-Li (HyakuretsuKyaku): Viper gets a mass of seismic hammers or focus unblockables off of this assist, however other things allow this and the assist is attached to Chun-Li.
Hsien-Ko (Senpu-Bu once in Rimoukon mode): The normal vulnerability to being popped by team supers/ dash back beams etc is dramatically minimized when paired with Viper’s high invincibility beam destroying super of her own, long block/hit stun, but of course it’s attached to Hsien-Ko.
** [FONT=Helvetica]Strong space control assists (Ranged):[/FONT]**
Spencer (Slant Shot): This assist lets Viper re-ground enemies for a lot of scary things, and perhaps most importantly is a low execution way of converting a full screen seismic hammer into a dead character.
Magneto (EM Disruptor): Likely the fastest full screen horizontal assist that on block or hit lets Viper do whatever she wants, decent in combos, single hit and high damage, helps her over all and is likely one of the best over all thanks to what it comes with.
Taskmaster (Horizontal Aim Master): The most combo friendly horizontal assist in the game, only 3 hits, leaves the enemy grounded if they started that way, decent start up, huge hit stun, high damage. Helps in controlling space and making combos do ludicrously more damage than they ever should.
Taskmaster (Vertical Aim Master): With this Viper can control far too much of the screen far too safely, much harder to use than other zoning tools but if used correctly Viper should always have control of exactly where the enemy is.
Storm (Horizontal Whirlwind): For some reason I always forget about some of the ridiculous properties Storm’s assist has, the amount it pushes people away paired with the amount of time it lasts for lets Viper go fully into her zoning game for massive chip and letting certain characters never really get in.
Zero (Hadangeki once in Sougenmu): A poor man’s Taskmaster horizontal arrows, that said Task arrows are so ridiculous that the poor man’s version is still quite ridiculous. Covers fatter vertical space than Task’s however.
MODOK (Floating Bomb): With Viper’s ability to keep people from throwing out obvious projectiles by punishing with seismo having such a long lasting space control element can be really powerful against certain characters who want to get in.
Other assist utlities:
Haggar (Double Lariat): Viper along with Dante and Doom make this already powerful assist even moreso, she can kill characters off of connected Haggar hits and it’s a terribly dangerous assist for others to deal with on either rush down or zoning Viper.
MODOK (Barrier): Needs to be summoned pre-emptively, if this is next to Viper and Viper’s next to someone they have the potential to be in a ridiculous amount of trouble. Viper can safely summon these at point blank with superior seismo strings and it gets stupid.
Felicia (Rolling Buckler): High/Low unblockable set up and moves people a very nice range akin to Storm, great for getting people to different locations depending on your game plan.
General assist strategy with Viper is to negate the areas she lacks strong control (high in the air either vertical or diagonal and absolutely full screen) or enhance the areas she already has strengths (Everywhere on the ground where the majority of the game is played) Even though she has the tools she needs for every situation some of these make certain match ups hopeless for your enemy. Since she has excellent mobility along with the ability to put grounded and normal jump height opponents into block stun at will she has the ability to most safely summon assists out of every character in the game, she has the ability to force a 2 on 1 where seismos blow up enemy summons while hers get to come out. The only exception is against highly mobile Magnetos (EM disruptor) and Storms (Float) where it can still be 2v2 thanks to their varying tools. Because she can force others to not use their assists at range or in moderate proximity often she should be abusing hers all day to push her lead. Thanks to how multifaceted her game play is she can either use assists to maintain or change spacing depending on the match up and remove options from other players giving her either free mix up, free chip, or free re-establishment of space.
Some general things she can do with assists: She can set up unblockables via focus attack or her extremely long range high hitting attacks. She can give herself time to link things after either early Thunder Knuckles, or later combo seismic hammers. She can block confirm to be able to either get to point blank or push the opponent full screen away. She can safely add chip to extend block strings. She can punish fish and blow up all punish attempts short of Arthur’s level 3 by putting out assists that would be risky for any other character. An exceptionally good use of assists is to compliment her seismic hammer game, whether it be Hidden missiles to re-establish timing and spacing, or horizontal aim-master to add ludicrous amounts of chip.
As far as DHCs are concerned with Viper they make it easier to kill characters but are not necessary to do so. DHCing out of either Burst Time or Emergency Combination are among the easiest in the game since at the end they cause a soft knock down high in the air which gives plenty of time to set up any kind of DHC including things that normally require DHC tricks. DHCing into her on the other hand is much less fortunate, on hit it’s fairly easy for a myriad of stronger characters, but none of her DHCs are remotely safe on block so bringing her in/out via them is exceptionally risky. That in mind, Emergency Combination has an absolutely idiotic amount of invincibility and will cleanly go through Bionic Lancer, Killer Illumination, etc, even if they’re started afterward. I believe after Hard drive and Gamma Crush it’s the highest invincibility level 1 in the game.
Viper’s best role is on point since Viper with assists has no truly bad match ups while there are difficult ones for her if she’s left to fend for herself against a potent zoning Mag/Sent, Dark Phoenix XF3, Zero/Doom, etc. In the center Viper’s assists become useful for a team, but the inability to DHC her in outside of combos limits her safety there. Alternatively her counters in can be incredibly strong. As anchor she is incredibly scary, but since her damage is already so high all that gauge and X-factor are better left to people who require them to get the kills.
I hope this is helpful DevilJin01! ^.^