Under Night In-Birth/UNIST/Vatista/Combos
Vatista has relatively few optimal combo routes, but many ways to reach them - you don't need to take screen position into account so much as you do starters/hitstun proration.
Vatista's combos will generally follow a Starter > Aerial > Landing > Ender pattern. Familiarize yourself with her various routes so you can switch mid-combo when necessary.
These starters all take the place of 2C > 5C in the above 2C combo.
5A/2A > 2C > 5C
- Hey, it's what we know and love. Just make sure you don't use 5/2B in between 5/2A and 2C.
5B/2B > 2C > 5C
- If you're careful that these don't whiff, they work great. 5[B] also works as a blockstring starter - 5[B] > 2C > 5C gives you time to confirm if you want to jC 5C on hit or release a Fragmentum on block. Alternatively, Reverse Beat to 5A, 5B (assuming you started 2B), 5AA (if you're close), etc.
j.B/j.C > 2C > 5C
- Jump-ins. What else can you say? If you use these off of an Assault, you'll need to use the j.B > (j.A >) 2A aerial route to get a Fragmentum combo.
66C > 6A > 2C > 5C
- If you hold 6 during all of 66C, it'll become a 4 on crossup and give you a 6A. Unprepared opponents may also block the 66C and not expect the crossed up 6A, still granting you the combo. If you don't cross up, you can burn Vorpal with 66C > FF > CS > 5C.
5C > FF > CS > 5C
- Useful if Vatista is too far away for 2C to punish in time, you want to CS for some meter, or you just weren't expecting to start with 5C. 5C > 2C > 5B can work for the latter as well if you don't have CS. 5C > 2C > FF > CS > Aerial will do slightly more damage, but works at shorter distances.
66B (ch) > 2C > 5C
- 66B knocks the opponent down on counterhit, meaning you can follow up with this.
These all come after 5C in the standard Fragmentum combo and are more or less replaceable.
j.[B] > j.C > 2A
- Basic air combo. Works.
j.[B] > j.C > land > j.A > 2A
- The land > jA is important here in increasing the range at which Vatista can hit with 2A, thereby increasing the range at which she can combo from. Allows you to get more hits out of j.C and 2A, so it arguably does the most damage, too.
j.[B] > 2A
- Useful if you're worried about your hitstun proration - it lets you land full Fragment combos off of Assault j.B or j.C and is essential for reaching the double laser landing route explained further down. Fairly hard to pull off though, since the j.[B] must be done as late as possible on top of requiring you to charge  during the startup of 5C. You can use j.[B] > j.A > 2A or j.A > j.[B] > 2A for a bit more leniency on the timing with little apparent change to the hitstun proration.
j.A > j.B > j.C > land > j.A > j.B > 2A
- Yeah, she can still do this. You won't be able to get a Fragment combo off of this, though. You'll usually go for this off of 5A anti-air, like in the 2B > 66C > 5A combo.
j.C > land > j.A > j.[B] > 2A
- Only usable when j.C is done on the falling portion of Vatista's jump, and as such isn't usable off of your standard starters. It is usable for routes involving aerial CS (8B > CS, FF > CS) as well as random j.C hits against airborne opponents. In the latter case, you may be better off using j.C > 5C > j.A > j.B > 2A to ensure it hits against opponents low to the ground for similar damage.
The all are assumed to come after an aerial 2A. Any combo with 2]B[ assumes that you were already holding B before entering this route.
2A / 2C > 2B
- Basic landing route that can't lead into anything other than 8X. Based on your combo's proration, 2C may drop, requiring you to use 2A instead.
2[C] > 2]B[ > 2A > 2B > 2]C[ > 4B
- The standard Fragmentum landing route. Get familiar with this, as this route is essential to reaching Vatista's optimal damage output.
2[C] > 2]B[ > 2A > 2B > 2]C[
- Same as the above, but time the 2]C[ release such that the second Fragmentum is popped by the first's explosion. Used primarily when you open with a Fragmentum, but also useful when one of your combos happens to run through a Fragmentum you previously set up.
2[C] > 2]B[ > 2A > 4A > 2]C[ > 4A/B
- The double laser route - it does slightly more damage, but it's a bit more difficult to pull off both in terms of execution and proration - there's a larger gap between 2A > 4A than 2A > 2B, so hitstun proration makes this combo impossible sooner than the single laser variant. To reach this route, you'll need to use a good starter and either the j.B > (j.A >) 2A or j.C > land > j.A > j.B aerial routes.
8B / 8C
- 8B midscreen downs the opponent far away, but allows you enough time to set up a projectile, Fragmentum or Assault to gain GRD. 8 midscreen leaves the opponent about 1.5 character lengths away with much less time to set up anything. 8B in the corner puts Vatista at a perfect distance to start the repeated Fragmentum string, or just general Fragmentum oki. 8C in the corner puts you almost point blank to the opponent with little time to set up.
j.C > FF > 2C
- Usable in combos after an opponent has been hit by the second (or more) Fragmentum. Holding  during FF drags the opponent upward, letting you get more hits out of 2C. It (usually) does more damage than a 8C ender, but keep in mind that if this is ending a full combo, the wall slam will almost always be impossible to combo from - that is, if they don't tech out before 2C's final hit (you're safe either way).
j.C > 2A
- Any aerial sequence (jC jB jA, jB jC, etc.) into A drill after a second Fragmentum more or less works. A meterless ender that does similar/slightly more damage than 8B and ends with better oki positioning midscreen. Generally a 2]B[ or 2]C[ crystal is released after the A drill, but keep in mind that like all Frag setups midscreen, backtech avoids everything.
- 5A > 5B > 2C > 5C > j.B > j.C > 2A > 2C > 2B > 8B (2537)
- Basic ground combo that gets you used to 2A and 2C OTG. Still a useful route to go to later on if you feel your starter has prorated your combo too much (Assault, especially).
- 5A > 5B > 2C > 5C > j.[B] > j.C > 2A > 2C > 2]B[ > 8B (2693)
- Slightly stronger and more complicated ground combo. Uses a single Fragment to get you used to comboing with them.
- 5A (anti-air) > j.A > j.B > j.C > land > j.A > j.B > j.C > 2A > 2C > 2B > 8B (2215)
- Basic anti-air combo that gets you used to j.C > land > j.A. Can connect off of many other moves, such as anti-air 66B/66C. You may need to replace 2C > 2B with 2A if used in a longer combo due to proration.
Damage values indicate base damage. "+" values indicate bonus damage from Vorpal (CS combos only). Note that slight changes in timing can change the amount of hits your moves do, so expect values to vary in practice.
- (2A/ 5B/ j.B/ j.C >) 2C > 5C > j.[B] > j.C > land > j.A > 2A > 2[C] > 2]B[ > 2A > 2B > 2]C[ > 4B > (8B (3240) / 8C (4059) / j.C > 2A (3308) / j.C > FF > 2C (4075))
- The standard Fragment combo. The button holding required to use Fragments mid-combo may seem difficult, but they're no big deal once you get the motions into your muscle memory. The 2C and 2A OTGs are a little strict, however - hitstun proration can ruin this combo easily if you're not careful with your starter or don't get a counter-hit (though the j.[B] > 2A aerial route will make up for the former). Still, there are a LOT of starters not listed that can get to this route. The damage for 8B/C assumes you do it after 4B - it's difficult, but you can swap it for 2B instead for less damage.
- (5B >) 2C > 5C > 5FF(whiff) > 9FF > CS > j.C > land > j.A > j.[B] > 2A > 2[C] > 2]B[ > 2A > 4A > 2]C[ > 4A > (8B (3973+162) / 8C (4923+162) / j.C > 2A (4040+162) / j.C > FF > 2C (4796+162))
- A CS version. The trick is to whiff the grounded 5FF, but hold 9 to make the second (airborne) portion hit. This uses the double laser landing route for additional damage.
- Explosion > 5C > j.[B] > j.C > land > j.A > 2A > 2[C] > 2]B[ > 2A > 2B > 2]C[ > (8B (3171) / 8C (4127) / j.C > 2A (3262))
- Standard Fragment combo that takes into account the fact that the opponent will tech after the first mid-combo Fragment by releasing the second mid-combo Fragment before they're knocked out of the first one's explosion. For the jC > 2A ender, you need to time the second Fragment's so it explodes from the first one's explosion - for either 8 ender, you can get away with being a little late since the Flash Kick will pop it.
2B All damage values assume the drill portion of 2B hits only once before the kick, as an instant overhead should.
- 2B > 66C > 5A > j.A > j.B > j.C > land > j.A > j.B > 2A > 2C > 2B > 8B (2629) / 8C (3240)
- Standard meterless combo from 66C. Hitstun proration makes 2C > 2B a bit difficult to connect from 2A, so you can use 2A instead.
- 2B > 66C > FF > CS > j.C > land > j.A > j.B > 2A > 2C > 2B > 8B (2895+174) / 8C (3506+174)
- A CS conversion for 0/100% bar.
- 8B > CS > 66 (delay) j.C > land > j.A > j.[B] > 2A > 2[C] > 2]B[ > 2A > 4A > 2]C[ > 4A > (8B (3644+152) / 8C (4416+152) / j.C > 2A (3629+152) / j.C > FF > 2C (4385+152))
- Yes, Vatista can combo off of Flash Kick with CS. You'll need to delay the j.C after the CS > 66 to let j.A hit.
- 2[B] > 2[C] > 2]B[ > 2A > 2B > 2]C[ > 4B > j.C (2A (2780) / FF > 2C (3388))
- Her standard Fragmentum route, but now in the corner. Just be sure to hold [B] from the beginning. 2C will whiff on Akatsuki, Byakuya, and Chaos.