Doing the trials in SSFIV requires a lot of fundamental knowledge. Click here for a refresher course.
Specials, her Super, and her Ultras
7: sc.LP, sc.MP
8: s.LK, cr.MP
Doesn't matter if you use the sc.LK or a s.LK for this one.
9: sc.MP, cr.MP
10: Seismic Hammer Cancel
Push any two punch buttons together during the startup of a Seismic Hammer.
11: j.MK, cr.MK, MP Thunder Knuckle
Special Cancel the cr.MK with the M Thunder Knuckle.
12: H Thunder Knuckle, Emergency Combination
Catch Dan with the H TK at any point near the peak of his jump, then hit him with the Super before he hits the ground. No cancelling required.
13 – EX Seismic Hammer, High Jump, Burning Dance
The trick to this is making sure you High Jump toward Dan as he flies up from the EX Seismo, and then input the Ultra as soon as Viper leaves the ground.
14: sc.HP, High Jump, Burning Dance
To make this combo work, you have to buffer in the inputs for a High Jump and the Ultra simultaneously. It can be a weird idea to wrap your head around, so I had to break it down to get it. First, I realized that by moving the stick from down, to back, to up/back, I could activate a High Jump while simultaneously entering the first motion of the Ultra. From there, all I had to do was add the second QCB+KKK to finish the Ultra. Practice this part by itself until it's easy, and then add the sc.HP at the beginning to bring it all together.
15: cr.LP, s.LK, cr.MP xx LP Thunder Knuckle, Emergency Combination
buffer the Emergency Combination (Super) in during the L Thunder Knuckle's animation. Simple.
16: EX Thunder Knuckle, LP seismic hammer, high jump, Burning Dance
Connect with the EX TK from a full screen away so that the LP Seismic Hammer that follows can connect. High Jump Cancel the LP SH jumping toward Dan, then quickly enter in the QCBx2+KKK to catch him with the Ultra before he hits the ground
17: L Seismic hammer, High Jump, H Burning Kick, Emergency Combo
Some bread 'n butter Viper stuff here. Make sure that you High Jump toward Dan after the L seismic hammer, input the H Burning Kick as soon as Viper leaves the ground, and then juggle Dan with the Super before he hits the ground.
18: j.HK, sc.HP xx H Thunder Knuckle, EX Focus Cancel, Burst Time
(corner) – Everything is pretty straightforward here, with one exception. You have to wait a split second after the EXFC to activate the Ultra. If you do it too soon, Dan will be too high and the Ultra will miss.
19 – Focus Attack, EX Thunder Knuckle, Burning Dance
This one can be a bit confusing. Dash forward after the Focus Attack so that the following EX TK can connect. When it does, jump back and input the Ultra. It seems like it needs to be buffered in so that Viper isn't high off the ground when the Ultra starts, but that's not necessary; it'll connect as Dan is crumbling from the EX TK.
20: j.HP, sc.MP, cr.MP xx M Thunder Knuckle, Emergency Combination
The only thing to know about this combo is that it ends with a Super Cancel, so you have to buffer the Emergency Combo in during the M TK. The rest is really straightforward.
21: Focus Attack, cr.HP xx Thunder Knuckle Cancel, Burst Time
Three out of four moves in this combo are multi-button inputs. It involves two back-to-back cancels, and it ends with what amounts to a 1-frame-link Ultra. This one is HARD. It was absolutely crucial for me to break it down. Start by getting very, very familiar with the timing on the TK Cancel. Start with a cr.HP, cancel into a TK of any strength (I just used the HP version), then hit any other two punch buttons to cancel it. The timing for the TK cancel is deceptive in that you have longer than you might think. If it keeps failing (that is, the TK keeps coming out), wait longer to push the two punch buttons for the cancel. Once you've gotten good at that, you have to finish it off by connecting with the Ultra. The thing is, the Ultra has to come out very fast after the TK cancel. So fast, in fact, Dan should still be doubled over from the initial cr.HP. It all starts coming together eventually, but you might notice that Dan winds up blocking the Ultra every time. This means you have to input the Ultra sooner. So again, the timing for the TK cancel is long, but the timing to jump into the Ultra afterward is insanely, brutally short. It can be mashed out, but that's not necessarily easier. Stay with it. Good luck.
22: j.HK, s.LK, s.LP, Burst Time
This one's pretty tough (and the very last SSFIV Trial I completed), but it's not too bad once you understand how to buffer it. The trick is to buffer in a QCF when you do the s.LP so that you can simply roll QCF, UF (this is the high jump – notice it goes from down to up)+PPP. You're essentially layering the input for the High Jump cancel over the input for the Ultra. If it's still confusing you, try this: standing close to Dan, hit a QCF+LP, making sure that a sc.LP comes out instead of a cr.LP or something like that. When you've got the hang of that, add a QCF, UF+PPP to it to activate the Ultra. When you get it right, Dan will have just started reeling back from the sc.LP when the Ultra animation starts. Once you get this part down, the rest is a cinch.
23: Focus Attack, cr.HP xx EX seismo, high jump, H Burning Kick, H TK
This combo is somewhat hard, but it's only a taste of what's to come. Dan has to be cornered or the last hit of this combo won't connect. The main parts to concentrate on are the High Jump Cancel and the H Burning Kick. For the High Jump Cancel, just be sure to A) allow enough time for the EX Seismo to hit before you try to cancel it, and B) jump either straight up or in toward Dan. The H Burning Kick has to come out very soon after the High Jump Cancel, otherwise it misses. Viper's pretty much ready to finish with the H TK the moment she hits the ground after the H Burning Kick, so input it as soon as she lands to catch Dan with it before he lands.
24: cr.HP xx Thunder Knuckle Cancel, cr.HP xx EX Seismic Hammer, High Jump, H Burning Kick, Burst Time
Let's see here... it's a cancel, a cancel of that cancel, a one-frame link that gets cancelled by an EX move... which gets cancelled by a High Jump, and gets finished by a special move, followed by an Ultra. Oh man. Alright, as always, I had to break it down. The first thing to get good at is the cr.HP, TK Cancel, cr.HP part. I just did this part over and over until it came naturally. From there, I worked on adding the EX Seismo. This can be made easier by holding D/F for the second cr.HP, and then moving the stick to down, then to d/f again to execute the EX Seismo cancel, but I didn't do that. Anyway, once again, I just kept doing those first four moves until they were coming out fairly easily. When I got to that point, I added in the last three moves. I kept messing up by not inputting the H Burning Kick as soon as Viper left the ground, but I eventually nailed it. That much is the hard part. After that, it's a simple matter of adding in the Ultra.