DBFZ/Vegeta/Strategy

General Tactics

Vegeta is able to play a strong neutral game based around his Ki Blasts and bully the opponent with his strong mix-up game, both with and without assists. j.S in particular is very strong in that air-backdash j.S is +20 at max range, hits fullscreen, and is nearly un-punishable. The property of Ki Blasts being special cancelable synergizes incredibly well with his 236X Rocket Kicks, as the opponent will more often than not get frame-trapped trying to jump after blocking his j.S; forcing the opponent to either make a Hail Mary reflect or DP fullscreen, or let Vegeta force his way in with 236M. For blockstrings, 236L leaves him airborne which allows for basic mixups with +30 blockstun assists, and true 50/50s (thanks to the float change) with +40 or more assists in the corner. His mixup game is solid even without assists thanks to 236H being a crossup and sharing VERY similar startup with 214H, an overhead that, when blocked, also leads into a 50/50 with assists, and his level 3 leading into a 4-way float-mixup after using 214S. To top it all off, Vegeta's damage output is among the best in the game, particularly in the corner.

Team Synergy

Point

This is Vegeta's best position. With the right assists, round start 3S + Assist can immediately start your offense, due to 3S sniping the opponent out of the air, and with 2 assists you can use one after 236M to continue your offense and the other to setup a mixup. His Ki Blasts hit at such an angle fullscreen that it'll catch the startup of every assist in the game fullscreen if your opponent mindlessly calls their assists during your zoning, simplifying the neutral for the Vegeta player. Vegeta's meter gain and damage is very high thanks to his Ki Blast loops and assist-friendly combo structure, making him a very strong "two touch" character.

Mid

Vegeta's combos are self-sufficient, but his ability to hit someone out of a blockstring gets worse as he has less assists to work with. A viable game-plan would be to annoy your opponent into Superdashing through your Ki Blasts and 2Hing them, or mix in an approaching IAD j.S during your zoning to force a turn. If you happen to make it in and you don't have assists, look to centralize your offense around his 5L, as you can 5L > DR, 5L > 236H, 5L > 214H, etc, creating very effective mental stack. His A assist is similar (albeit weaker) to GT Goku's old A assist as it covers full screen jump height and has decent hit-stun, but has a thin hitbox leading it to whiffing more often than not at it's intended angle. Unfortunately, his other assists are not really comparable in usefulness. If you're insisting on playing him mid, pick a good battery for a point and look to tag him in to abuse the oki off his 214S > 214L+M.

Anchor

Vegeta's neutral is very strong by himself and can utilize the bar your point and mid built very efficiently thanks to ...214S > 214L+M, making him a surprisingly viable anchor. His assists are decent but do very little outside of combo and blockstring extensions compared to other anchor characters. Vegeta is generally better earlier in the the team as he gains a lot from assists, while not having any noteworthy assists himself. His incredible neutral and damage can still win you matches even if he is on anchor, but you'll be relying on your opponent being impatient or very efficient mental stack to open up your opponent this way.

Recommended Partners

Vegeta likes high-blockstun assists, as he requires 40+ frames of blockstun in order to create gapless 236L float 50/50s in the corner. Notable examples from strong characters you may run with Vegeta include Kid Buu A, Lab Coat A, and Janemba A. Vegeta can also get gapless 236S 50/50s using multihit assists with 40+ frames of blockstun, but this is not required as the opponent will have to risk double reflecting anyways to escape the mixup. Instead, you want assists that don't have much pushback so that you can get his 2L to land midscreen. This includes A. Gohan/Kefla/Gotenks B, Vegito A, and Piccolo A. For neutral purposes, Vegeta doesn't need much, but having DP or barrier assists to cover right below him can be useful, as he has a bit of a vunerability right beneath him. This includes Cooler/T. Gohan/A. Gohan A, A17/A18 A, and Labcoat B. And if you're looking to lean fully into the neutral control aspect of his gameplay, try out assists like Piccolo A, Janemba A, and (most notably) Vegito A. Finally, any assists that allow Vegeta to get 214S even after using 214M/H in a combo (usually after a 2H which you'll get a lot) are excellent. This includes Blue Goku A, Baby B, and every C assist in the game.

Overall, contrary to popular belief, Vegeta is not extremely picky with his assists. His 236S can create RPS scenarios which lead to a 50/50 with any assist with 20+ blockstun when blocked. His neutral is encompassing enough that he does not necessarily require specific neutral assists to perform well.

Blockstrings

5L/2L > 4L > 5LL > 5M > 2M > 5S > 5H > 236L

Safe normals: 2L, 5L, 5LL, 5LLL, 2M, 5M, 2S, and 5S. 5L is notable as it is -2, allowing you to backdash and punish a whiff if you so choose, and can gatling into itself for staggers. At the end of strings it can be better to use 236M midscreen, due to it being easier to extend your blockstrings with an assist and its ability to cross through the opponent on block creating distance, but overall its safer to use 236L as you're airborne and you can setup RPS that can potentially steal another turn even when you're down assists.

Mix-up tools:

236L High/low 50/50 (50+ blockstun)

...236L > j.2H (whiff) > airdash j.L
...236L > j.2H (whiff) ▷ 2L

Popularised by SonicFox during the end of season 2, this mix-up requires huge blockstun (like a certain pink bois assist) to jail properly and is a complete guess between low or overhead.

Corner 236L High/low 50/50 (40+ blockstun)

...236L > hold 9 to float towards your opponent > airdash j.L
...236L > hold 9 to float towards your opponent > ▷ 2L

Rocket kick RPS

...236L > airdash j.ML
...236L > j.S
...236L > backdash/airdash j.S
...236L > j.236L

236S High/low 50/50

...236S > airdash j.L
...236S ▷ 2L
...236S > airdash j.M
...236S ▷ 2M
...236S ▷ DR

Vegeta's least demanding mixup. 236S can be reflected in blockstrings, but because reflecting 236S has no pushback, it leaves both players in an RPS scenario where:

Vegeta baits the followup reflect/uses DR to beat the reflect
Vegeta continues the mixup as normal, but gets reflected
The opponent reads the reflect bait and steals their turn

Solo "Mental Stack" Mix

5L/4LL > DR
5L/4LL > 236H
5L/4LL > 214H
5L/4LL > 6M
5L/4LL > restart pressure
5L/4LL > (delay) 5LL

If you ever find yourself without assists, try to centralize all of your pressure and mixups on Vegeta's 5L to get the maximum out of putting mental stack on your opponent.

Okizeme

214X Options

214L leads to a basic meaty with 214L[6] > 2L (whiff) > IAD. All of his air normals will catch uptech. If you catch them up-teching, route into a medium button as fast as possible for gapless Superdash mixups.
j.2H is a great tool for wake up mix in the corner as 214X will leave you in the air. j.2H pushes Vegeta forward a little bit, leaving him in the air, so you can go for airdash high, fall and go low, or land into DR if you use an assist to meaty back-tech or delay-tech.

You can also use it raw to meaty up-tech and get a solo 50/50 once they land

Another post 214L tool is j.1S/2S. Use j.1S in the corner and j.2S midscreen. Throwing this out before you land forces your opponent to block without putting yourself at risk, but because it is a ki blast, it can be superdashed through on block.

If your opponent likes to delay tech through your j.1S in the corner, you can throw an additional j.1S out before you land to cover a LARGE majority of the delay tech frames.

If you happen to knock the opponent down with 214M instead, using j.1S frame-kills so that you can go for an immediate IAD j.L/M/H safejump once you land.

Dealing With Delay-tech

Unfortunately, Vegeta lacks moves that have enough active frames to be used as reliable meaties against characters with 4-frame reversals, so if you're unwilling or unable to use assists to meaty for you, your best bet is to use 5[S] and react to superdash with 2H. Another option would be to react to the delay-tech with an assist call and a superjump-fastfall so that you get a 50/50.

Post Level 3 Mixup

Vegeta gets a basic IAD safejump from his normal level 3. 236S is also good to use after his basic 214L+M, as it sets up a the same 50/50 as normal when paired with an assist as a meaty
There are two ways to setup mix off of Vegeta's powered up 214L+M, thanks to the additional oki off of 214S. The first utilizes j.2H and looks like this:

j.2H > airdash j.L
j.2H ▷ 2L

The high option will more often than not just safejump if the opponent tries to 2H you, while the low option will counterhit them out of it.

j.2H mixup video example, bot set to 2H

The second utilizes the float aspect of superjumping and is FAR more effective for mixups. The easiest way to do this is to input a superjump as the background begins to fade back in and immeditately airdashing (the whole input will look something like 2[9](66 or 6HS), or [S][9](66 or 6HS) if using the superjump macro). It takes some practice but the payoff is definitely worth the effort. Your options will look a little like this:

sj.IAD[7] > j.L (same side high)
sj.IAD[9] > j.L (crossup high)
sj.IAD[7] > [2] ▷ 2L (same side low)
sj.IAD[9] > [2] ▷ 2L/DR (crossup low)

214X[6] (whiff) > j.L sets up a crossup which will catch those who are unaware. Just for clarification, this too is only after a powered-up 214L+M.

Float mixup video example, bot set to 2H

Tips and Tricks

236M uses up your smash attack, but in the corner, it wall splats and allows for solo snap.
Doing j.2H > j.214L almost always allows for sliding knockdown if the combo isn't too long, but if you go into level one super afterwards, it may whiff.
j.214M[6] and j.214H[6] combo into 214S, but not j.214L.
On some characters, an instant-air j.2H can connect even if your opponent crouch blocks, leaving you +3.
If you think your opponent is going to reflect your safejump, you can use your j.S to safejump instead which forces the other player to risk double reflecting if they want to create distance. You can also use j.S as a jump in or crossup as well, since it'll beat 2Hs.
If you know you'll build enough bar for a level 3, but not enough to get j.214H, you can opt to save your j.2H up-smash until the end of the combo to get the j.214M knockdown solo and meterlessly.
236L+M always gives Vegeta a sliding knockdown (and a safejump if you're low enough to the ground) at the cost of 1 bar. This can be useful for characters like A. Gohan who wouldn't have the SKD otherwise after a DHC, or off of Vegetas more damaging combos where you use both your up and down-smashes early in the combo (5H -> (delay) 214M + Assist is a notable example).
Try not to use backdash j.S too often. As powerful as it is, if the opponent gets a read on your timings they can preemptively superdash and punish you, even from fullscreen. It's best to mix in 5(S) and 3S from time to time as they can both still snipe your opponents assists while being less committal, allowing you to 2H, reflect, and vanish (without whiffing and getting punished anyways) if they do superdash through them fullscreen at the cost of being less plus on block.
214H has EXCEPTIONAL tracking when your opponents are holding towards you. If your opponents try to superjump over your zoning, it can be worthwhile to 214H while you're offscreen to potentially catch them off guard. It will whiff if the opponent holds away from Vegeta, however.

Fighting Vegeta

Vegeta IAD j.S leaves a blind spot in front and above him in the air. If you try to challenge him on the ground, you're going to be fighting a losing battle. The only way Vegeta can challenge you above him in the air is j.214X and j.2S, which are far more easily countered than IAD j.S.
If he does the j.2H mixup, its technically not airtight unless the assist has 44+ frames of blockstun (gotenks A, Kid Buu A, Kefla B, Bardock B, Roshi B, and some C assists) so you can reflect it, just be wary of him landing and going low with 2L.
If you react to an EX flash in time, your best bet is to superjump away from where Vegeta previously was to make both the Knee Drop and Rocket Kick whiff.
Vegeta is extra susceptible to reflects, due to not having any anti-reflect normals, and the only anti-reflect tools he has (Rocket Kick and his Knee Drop) can put him at risk. If the Vegeta player doesn't react appropriately, you can usually 5H or call an assist to steal a turn or outright punish them.
Down-teching, as is the case with most "loop" characters, is a terrible idea. More often than not, if the Vegeta player drops a corner combo and you down-tech you'll still be at a disadvantage, but now with less health. Your best bet is to forward-tech or up-tech out of his air-combos.