Those who've been following the comment sections on Sol vs Ragna, the previews, and the thread in the forums, should know that I've been one of the more prominent posters arguing in Gaara's favor. With the episode out now, and Toph being victorious, I think it's appropriate that I voice my issues with their reasoning.
Let's start off by examining their claims for why Toph would win.
Toph can sense earth in the air so she can always tell were Gaara's attacks are coming from.
Being able to detect an attack is one thing. Being able to actually block/avoid it is another. Having 360 degree vision is definitley advantageous, but it doesn't mean much when your opponents attacks operate at a level of power and speed you've never shown to be able handle. I'll get to that later. Additionally, ever since part two, Gaara has fought primarily in the air. Among other things, this gives him a much better view of the battlefield, meaning he'll also be able to see and intercept any attack Toph can throw at him. This isn't an advantage for Toph, it's simply a lack of a disadvantage.
Gaara's sand is still sand, so Toph would be able to control it.
Two problems with this, the second of which I'll elaborate on later.
The first problem is that it assumes that Toph is capable of controlling living sand. It's made very clear in the avatarverse that bending an element that is "living" is extremely difficult and requires much practice. There's a reason why bloodbending is only known to a select few, requires training, and can only be done during a full moon(excluding a small number of individuals who can do it without a full moon, but that required large amounts of training on their part), when waterbending is at its strongest. For those claiming that the difficulty of bloodbending is because of the mixture of water with other impurities, that's never been stated to be the case, and frankly wouldn't make much sense. Water is water, there's no real reason for why a water benders ability to bend it would be affected by any other substances surrounding it. In addition, if it was simply a matter of precision, then the full moon wouldn't be necessary in order for most bloodbenders to bloodbend. The full moon greatly boosts the raw power of water bending, but there's no evidence that it allows waterbenders to bend with more precision than they normally do. Finally, in Legend of Korra, bending is never presented as an option in dealing with the spirit vines. Korra was forced to go into the avatar state and use energy bending in order to subdue them.
The second problem is that this assumes that Toph even has the raw power or speed needed to be able to deflect Gaara's attacks in the first place. This is not the case.
This is a bit of an aside, but it's also worth mentioning that Gaara's sand control does not work like bending. When he sends sand after someone, he maintains control over it. Meaning, Toph couldn't simply push it to the side to set it off course, as it would be constantly homing in on her. Raising rock walls to block it would also be futile as the streams of sand could either go around them, or simply bore directly through them. The way DB depicted Gaara's sand working like simple thrown projectiles was extremely innacurate.
Gaara's sand contains gold, which gives Toph more "bending options."
I rolled my eyes particularly hard at this one.
First of all, there isn't any solid evidence that gold became a standard part of Gaara's arsenal and wasn't just a one time thing.
It's been confirmed in the Gaara Hiden novel that he no longer carries gold in his sand.
Second of all, Toph has never been shown to be able to control such tiny amounts of metal. Her metal bending works by pushing on small impurities within the metal to force it to bend. The assumption that she could bend metal the size of a speck of dust is tenuous at best.
Third of all, even if we grant that Gaara's sand has gold in it and she can bend it, how exactly does that provide Toph with an advantage? There isn't any evidence that she can apply more force to metal than she can to sand. Not to mention that whether or not she could control his sand in the first place is extremely questionable, as I've mentioned above.
Gaara always keeps himself covered in his sand armor, so Toph can always sense where he is. His armor uses up large amounts of chakra and Toph could use it to crush him.
A lot of problems with this.
1. There isn't any evidence suggesting that he perpetually keeps his sand armor up. In fact given that it drains his chakra and encumbers him, it seems more reasonable to assume he only puts it up when his automatic defense is in danger of being breached.
2. Later on in the series Gaara has been shown to have very large chakra reserves and capable of using successive large scale attacks and taking heavy damage without succumbing to exhaustion. They provided no good evidence to suggest that Gaara would be tired out before Toph, or that Toph even had the means to pierce through Gaara's automatic sand shield.
3. Just because Toph can sense the location of earth in the air doesn't necessaraly mean that she can sense fine details like shape, so she would have no real way to distinguish between Gaara and the sand he's standing on. Even if we give her the benifit of the doubt, he could still easily throw her off with sand clones.
4. Gaara has been shown to be decently smart and tactical throughout the series. If he were ever facing another opponent with geokinetic abilities, it's really not a stretch to say that the first thing that would pop into his head is the sand armor surrounding his body, especially since he specializes in crushing attacks. It stands to reason that he would remove it, if he was even wearing it in the first place.
5. Gaara's gourd sand is literally programmed by his mothers soul to protect him at all costs. As I previously mentioned, bending spirit possessed elements is very different from bending normal elements.
6. It assumes that Gaara couldn't simply fly out of Tophs range. Even granting her the ability to detect earth in the air, there she has never shown to be able to detect to airborne earth from much more than fifty feet away.
Now, a comment on the animation.
I'll try not to nitpick too much because I know that the animations place more emphasis on being entertaining than as serving as a one hundred percent accurate reperesentation of the fight.
Toph being able to easily survive his sand coffin with metal armor is absurd.
In addition to everything I've already said, it's been confirmed in the previously mentioned novel that Gaara possesses "magnet release" which allows him to control metal. In other words, Gaara can now crush Toph in her own metal amor without even using sand. Irony's a bitch eh? Also, he now uses a more heavy metallic sand.
Early in the series, Gaara fights a character named Kimimaro, who's bones are stronger than tempered steel.
Gaara traps him in a sand coffin, and he admits that if he had not grown an additonal layer of bone of armor to protect himself, then he would have been crushed. Also worth mentioning that he was also forced to go into stage one of the curse mark transformation, already gives a boost to base durability.
As if this wasn't enough evidence, Gaara proceeds to attack and bury him under a giant sand tsunami, terraforming the forest around them into desert in the process.
He then uses a giant sand burial that spans over the entire area he terraformed.
Kimimaro is again, forced to transform, this time into his final curse mark transformation state.
This makes it clear that Gaara's second attack would have been strong enough to crush him even with the new bone plates he grew under his skin. After all, Kimimaro was suffering from a crippling illness when fighting Gaara, so it follows that he would want to strain himself as little as possible. Curse mark transformations place heavy strain on the body, so he wouldn't have used it unless he absolutely needed to.
Also since Death Battle was allowing filler feats, Gaara was also heavily implied to be capable of crushing Mecha Naruto, a murderous robotic version of Naruto(yes, this is real) who had previously been rampaging through the Leaf Village with no one being able to stop him.
Even ignoring this, Gaara's sand could have still easily slipped through any openings in the metal armor and killed her right then and there. There would have to be openings in order for her to not sufficate.
Now as for why Toph should not be able to deflect Gaara's attacks. We all know that Gaara is capable of manipulating a massive amount of sand at once. The amount of energy required to manipulate such a large amounts of earth already places him at a level of power far beyond anything Toph has ever faced. Since Gaara's sand manipulation is ultimately just chakra control, there's no reason for why he shouldn't be able to place this much force behind his attacks. This is supported by the fact that with a tiny amount of sand, he is able to physically restrain Sage Mode Madara, the same guy who was easily able to knock all the tailed beasts flat on their asses. To put this into perspective, here's how much physical strength a much weaker character than SM Madara had. http://www.narutoforums.com/blog.php?b=15539&page=...
Not to mention Gaara's sand can move(at the absolute least) faster than eye can see, DB even admits this. Though it really is much much faster than this if we take into account speed calcs(Here's one from the chunin exams that already places his attack speed in the hypersonic range, the result in the blog is around mach 4 but it get reworked to mach 17 in the comments). If we use power scaling then he becomes even faster than that, as he has been able to intercept some of that fastest characters in the verse, including the third raikage with his lightning chakra cloak, and Madara Uchiha, one of the most powerful shinobi who ever lived. Toph has no speed feats of her own that are even supersonic. She has one that may be faster than eye can see from her confrontation with The Boulder, but that's still nowhere close to enough. I believe Korra had a feat of reacting to an explosion which she could be scaled to, but if we're to include scaling, then Gaara can be scaled to speeds like this http://www.narutoforums.com/blog.php?b=19929
A few miscellaneous points.
DB never factored in how sealing tags would effect that battle, even though they did acknowlage that Gaara had them. For those who don't remember, anything a sealing tag is placed on is "sealed" ie. completely immoblized. Gaara would simply have to throw a sealing tag on Toph or any substance she's incased and she would be completely paralyzed. Even granting all of DB's assumptions, this is still a game changer.
In "The Last: Naruto the Movie" Gaara include Futon(wind) at the beginning of his jutusu incantation indicating that he's capable of using wind natured chakra in conjunction with his sand.
In the new novel there is more evidence that Gaara now incoperates wind into his attacks. He has a tecnique called Futon: Yae-Hayate, that basically allows him to create barriers of wind. He uses these in conjuction with his sand defense.
Finally, let's look at what advantages both combatants have over one another, to really put this into perspective.
Range(can control sand from over a kilometer away)
Manuvarability(even academy ninjas have shown far superior acrobatic skills to anyone in the avatarverse besides maybe Ty Lee, being able to leap dozens of feat in the air. He also has the body flicker tecnique)
Air superiority(self explanitory)
Speed and reaction time(see above)
Durability(blocking nukes, city busting meteorites, a slash from Madara's susanoo sword, etc)
Close combat capabilities(which is now relevant given that Gaara uses CQC tecqniques now in the form of the Sand Sword, which was revealed in the new novel"
Control over a wider variety of substances(sand, metal, air)
All in all, I'm disappointed with Death Battle, and can confidently say that I won't be watching it for anything more than pretty animations.
Thanks for reading.