Nice stuff Fink, here’s what I do with Ammy assist, some of it’s really basic and most people probably know about it, but I’ll go ahead and just list everything for the sake of having it all down.
BnB Mixup:
Crouching Light + Cold Star -> Crouching Light -> Crouching Light -> Crouching Light -> …
Simple idea; the goal is to just cover Cold Star’s activations with lights so they’re forced to block it. Once they’re in blockstun you’re free to 50/50 them with Mirage Feint Cancel mixups or even go for Fuzzy Guards if you’re feeling brave. Downside to this is occasionally people will just pushblock you away and escape, but X-23’s anti-pushblock game is so powerful that that’s not too hard to persuade them not to do. Something as basic as just staggering your crouching lights will teach them not to do it. A friend of mine once said that if you ever get someone to block Cold Star, it should be a kill every time. Words to live by.
Incoming Mixup 1:
Death or Snapback -> Dash back -> Cold Star -> Mirage Feint M
Another basic mixup. Depending on how far you dash back and when you do the Feint it can be really ambiguous as to what side to block. If they get hit I suggest going for either a TAC or a TAC bait reset because Cold Star will scale the damage horrendously and you’ll almost never get a kill off of it otherwise. If they block it just mix them up like you would with the BnB. The downside to this is that anyone with an airdash or any kind of aerial mobility can just get out of this for free, but that can be taken care of with other variations.
Incoming Mixup 2
Death or Snapback -> Dash back -> Cold Star -> Super Jump Forward -> Talon Attack H -> Falling Claw
Another really ambiguous setup where the hit depends on when you super jump out of the backdash. I like doing this against characters that have some air mobility, but not airdashes. It’s also a lot safer to do against characters who can come down with moves like Helm Breaker and Footdive. Same things apply as the first one, if you get the hit go for a reset off of TACs. If they bock, mixup time. Downside to this is, again, some characters can airdash out of it, and unlike the last mixup you can also get airthrown. So anyone with a long airthrow animation will just completely bypass Cold Star.
Incoming Mixup 3
Death or Snapback -> Meaty J.L + Cold Star -> J.M -> J.Talon Attack L
This is the no bullshit setup because as far as I know nothing will beat a meaty J.L on incoming other than Harddrive and Morrigan’s level 3. It stuffs Foot Dives, it stuffs Helm Breakers, it stuffs whatever. The goal if this is to just force them to block Cold Star and fall to the ground where you then apply the standard mixups. If they do get hit by the J.L you can go into whatever setup you like off of it, they’ll fall into Cold Star so again I suggest TAC or TAC bait resets. This is pretty much an all purpose setup and will always give you a chance to run shenanigans. I guess they could X-Factor guard cancel through and grab you, but I wouldn’t worry about that too much. Just X-Factor back and kill them meterlessly, then Dirt Nap the third character. If they want to encourage you to use Dark Laura that’s on them. The only downfall to this is that it’s just one mixup opportunity as opposed to the two you get with the above. But at least it’s more reliable.
THC Mixup
Self-explanatory. X-23 can’t take advantage of the THC as well as Doom or Strange can, but you can still do it. Pop the THC, wait for Rage Trigger to end, dash over and Mirage Feint. Chances are they’ll get hit by it since it’s really hard to see where X-23 is going. I don’t go to this option a whole lot so I don’t actually know if it’s possible to keep them standing by doing Mirage Feint cancels into Talon Attacks, but if not then you just need to OTG and pop X-Factor to pick them up after the lighting knocks them down. It’s meter heavy and uses your X-Factor so it’s an expensive option, but it’s got its uses. I use it in those odd situations where my Dr. Strange is dead but my X-23 is still alive and they’re down to their anchor. By doing this you get at least one chance to avoid dealing with an XF3 character.
Slow shenanigans
Weapon X Prime -> Veil of Mist -> Raw tag -> Combo
Basically anytime you land a raw WXP and have Ammy behind her, you can go into a slowdown and then, if timed right, raw tag back to X-23. She’ll hit them as she comes in and that will give you enough time to continue the combo. The damage you get won’t be spectacular but it’ll be more than what you would’ve gotten. Alternatively you can just do a slow combo as Ammy using Lightning Edge and get the same (More?) daage, but I like the hard tag combo because it gets X-23 back in.
I think that’s pretty much all I do. Basically just anyway you can get someone to block puts you in a great position. Also if you play a second character who doesn’t have an infinite, it’s worth finding a way to TAC through them directly to Ammy and going into her infinite to hopefully set up a double dirt nap.