However, her armour that she has on her MEKA reduces the damage that D.Va as able to take. Should she get caught by any fire blast, it wouldn't affect D.Va too much. Something like Winston's Tesla cannon requires multiple charges, and reloads, to get D.Va out of her MEKA. If anything, D.Va is a hard counter to Winston, because of her durability in the game, and the ability to keep up the pace. It'll be a similar situation with Alduin.
Like I said, the Tesla Cannon is meek, especially when compared with the breath of a dragon on the scale of Alduin. Armour helps absorb any damage that would normally caused to herself, but as mentioned above, a couple of rounds of ammunition from a Soldier 76, or a McCree can get her out of the suit. The ferocity of Alduin's fire would be more than enough to make the suit useless, or at least trigger a self-destruct.
I won't take long on these points, as I believe they're either moot, or I could argue the same thing for Alduin.
Shouts, and fire breaths, would have a similar cooldown; Alduin from behind cannot defend himself; the Defense Matrix is a defense tactic, how can one be defensless when she's defending herself?
Let's move on to more of the meatier arguments.
I can concede that the shouts may have a cooldown. But these are cooldowns on offensive abilities. D'Va's cooldown on her only ability relevant in this battle is purely avoidant.
Alduin at least has a tail he can use as a melee weapon. D'Va has absolutely nothing to defend herself from behind. And given his weight, and D'Va's inability to block melee weapons, this could perhaps be another way he could disable the MEKA.
Defenceless with regards to this battle. D'Va's Defence Matrix is useless at blocking either the shouts (not enough density) or the melee attacks (not a ranged attack). It is literally hopeless in this battle.
Yes, you are correct on D.Va blocking Hanzo; however, it takes time for Hanzo to get something as powerful as an Ult ready, very similar to Alduin when he goes for the shout. Being nimble on the trigger, and having a very good sense of predictability (since, after all, FPS gaming revolves heavily around predicting opponents, and trigger discipline), D.Va should be able to detect Alduin's attacks, and either evade with her boosters, or use her Defense Matrix to prevent them from occurring.
Alduin is a big dragon. They're not exactly fast.
All Alduin has to do is say a phrase in order to perform a shout, something he could do extremely quickly. Hanzo actively has to channel his bow, shout a longer phrase, fire his projectile and wait for it to transform into a pair of dragons/wolves. The comparison is in fact a contrast.
I'd also like to mention that D'Va's expertise with regards to gaming is not FPS games (not that she'd be bad at them), but RTS games, like Starcraft 2, which require a completely different mindset to an FPS game. Of course, D'Va's good enough to be a part of Overwatch, so she must be doing something right in that regard, but a fight against a being like Alduin (even if she has fought some mechanical abominations in the past) is a fight she will have never had to cope with before. You can make the argument "Well, she might have played Skyrim" but A) There is no guarantee that Skyrim exists in the Overwatch universe and B) Even if it did, she would be playing as Dragonborn. And D'Va is not a Dragonborn.
Alduin is from a realm of magic, yes, this is true. However, technology doesn't technically exist in his world, in the terms of how we view technology in the modern times. D.Va is from the future, about 60 years into the future. The technology available in the future would have advanced so far that magical entities could be understood by science, or created from such. In fact, in her world, such "magic" can be replicated, like teleportation, blink teleporting, ice spells, etc.
No, technology does exist in the Elder Scrolls universe. They have advanced far beyond the point of beating people with sticks and stones. I'd say it's around the early Medieval era period with regards to technological innovation. And that's not even factoring in the marvels of engineering the Dwemer were capable of. I know what you're trying to say with regards to a lack of gadgets, but to be honest, I find it to be a moot point.
The key word is "replicated" also. This isn't actually magic. It's technological advancement. All magic from the Elder Scrolls games has been proven to be a creation of the Aedra, powerful deities. There's a big, big difference here. Not to make this a controversial religious discussion, but the influence of the gods in Alduin's world far exceeds that of the influence in D'Va's world. Technological advancement is great, but it's still far, far away from what the gods have been proven to create in the Elder Scrolls universe.
May I, once again, direct you to the year in which these suits were created? Very far into the future, so the "lag" you believe would be inside the suit can be argued that it's a null factor. I'd go as far to say that it isn't a problem.
This isn't an argument about the technological aspect or lag. You say D'Va's reaction speeds are legendary. But the suit itself is actually very slow to move. And as I said before, maybe she's accustomed to it, but it doesn't change the fact that D'Va, with her fast reactions, is working with a slow suit, which in turn is a disconnect between complete control.
Excellent argument.
However, it's the same problems that the Dragonborn had to encounter. You couldn't sprint forever, and in such a time, you'd have to hide away and dodge when Alduin came for the spin. Yet, he managed quite well. D.Va, whilst not being the bane of dragons as Dragonborn was, still possesses a similar arsenal of firepower, and evasion tactics, that Dragonborn had at his disposal... with better technology, and a heightened sense of reaction time. I'd wager to say she'd manage as well as Dragonborn in such a fight.
Thing is, the Dragonborn, when not sprinting, was much faster than D'Va when not thrusting still. And was also a much smaller target when outside the suit, whilst being much more durable than Pilot D'Va. Not to mention his access to magic with regards to wards and dragon shouts.
South Korea had an invasion of large monsters, and everyone was collecting shitting themselves because none of the regular army could do anything. Enter D.Va, a member of an elite battalion who could only deal with such monsters that invaded the cities; a last hope, if you will. This is in OW lore, and is similar to the Skyrim lore, of Dragonborn and Alduin.
What happened in both scenarios? The monsters were defeated. In the case for D.Va, these monsters weren't even bosses in a video game. They were real life threats that were troubling the city, and one false move could render her life in jeopardy. She has been trained to take on the biggest, and the baddest, without having to result in losing lives. Alduin is no different here.
Firstly, Alduin isn't just an average large monster. He is the Nordic God of Destruction and considered the World Eater. It took divine intervention, which we've established is more powerful than any technology readily available in the Overwatch universe to stop him the first time, and absolutely perfectly set conditions to stop him the second time, and even then, it took 3 other heroes to actually assist in stopping Alduin. To say he's just another large monster for D'Va is pretty insulting to Alduin.
Secondly, you mention battalion. Plural. It seems as if she actively needed assistance in taking down these monsters, and there seems to be indications of casualties, seeing as D'Va is the only one in the Overwatch lore we see with a MEKA suit.
So, in summary, she took down creatures far less potent than Alduin, with assistance from her battalion, with her battalion most likely suffering heavy casualties. Not as impressive.
Alduin isn't the body size of Tracer, and D.Va can melt through any target that has a large body, much like Alduin. Bigger body = more chance for her bullets to connect.
However, this argument suggests that Alduin remains in the sky for the entire battle. Wouldn't make for an interesting battle if Alduin is in the sky the entire time. He'd have to come down at some point to take out D.Va, and any extra time spent flying means more charge for her self-destruct, and analysing a game plan.
Bigger body = higher accuracy is correct. But my example was assuming the Tracer was standing still with perfect accuracy from D'Va. Even then, it would take a fair amount of bullets to put Tracer down. And it only gets harder the more bulky the enemy is. And Alduin is on a far, far higher echelon than even a fully armoured and shielded Roadhog.
And my argument isn't assuming Alduin would be constantly airborne. Remember, I did say Alduin would land in how I thought the fight would play out. And firing at Alduin during the aviation phase would not only be futile, but make D'Va even more of a target for his fire, and make the battle even shorter for D'Va. She would be best just to use her boosters and trying to hide and nothing more during this portion.
Alduin is an extremely big target, and D.Va has a variety of ways to put the MEKA in self-destruct mode, and launch it at Alduin without him having enough time to detect it. Remember, this isn't magic he's seen before, and will probably never see in his life time.
Alduin isn't stupid though. If he saw a suit flying towards him, D'Va's main asset, he'd suspect some kind of trap and throw it to one side, hoping D'Va would not be able to utilise it again (he'd be unaware of D'Va calling down another MEKA though I imagine, but as I said, he'd capitalise on her in pilot form). And even if it did by some chance hit him, it wouldn't do that much damage. A Roadhog at full health can survive it, so why wouldn't a being as omnipotent as Alduin shrug it off?
I think the problem here is bullets and self-destructing MEKA's, and their effectiveness against a dragon who deals in arrows and magic. The latter two options are both outdated technologies, replaced by much more reliable, and faster firing, ammunition, and the magic replicated by science and technology, again, being more reliable to utilise. Whilst we do not know how bullets and machine bombs would fair against Alduin, I can argue that they are better than what Alduin had to deal with, and then using this, assume the damage output to be more reliable.
OK, bullets are more advanced than arrows. But they accomplish the same thing, which is to pierce and incise, it's just that bullets are more reliable to work with. So why is it that D'Va's bullets take an eternity to shred through a Roadhog without any armour or shield? And why is it that it requires far, far less of Hanzo's arrows to take down a Roadhog? Not to mention Alduin's virtually impenetrable scales and massive bulk is a big step up from a Roadhog.
Also, Alduin has had to cope with explosions before. Plenty of spells in Skyrim are capable of causing explosions, and Alduin shrugs them off. Why would a MEKA explosion be any different?
Yes, it's a different perspective of the fight, but we know D.Va is capable, and has fought against, people with similar attributes to Alduin, and can actively compete against them. Alduin has yet to fight against someone as advanced as D.Va, and I cannot see any proof within the Skyrim world, do illustrate such advanced power.
D'Va has not fought against anyone from the same book, let alone the same page as Alduin. And the powers of divinity transcend that of technological advancement, as established above.
D'Va puts up an admirable fight, but there's absolutely nothing she can do to put Alduin down. And to be honest, Alduin is a Uber tier character. I don't expect anyone to be able to take him down, unless either specially equipped to do so (Dragonborn or Hiccup Horrendous Haddock III) or an even more powerful entity (Faceless Void).