Azir vs Noxus

I feel like one has to consider the fact that Azir is already in a war against Xerath. Granted, that conflict is currently at something of a standstill as far as we know, but if Xerath sees another army coming in from the north to attack Azir, he's probably the sort of character to capitalize on such an occurrence. He might force Azir into having to fight on two fronts, or he might even decide to take some of Noxus's soldiers for himself, since we know he can apparently mind-control a whole armor (seen in the Bloodlines story.) As it stands, Noxus would probably just serve as more of a nuisance for Azir, but one that his real enemies could take advantage of.

If Azir were leading a united Shurima, though... Then yeah, Noxus gets stomped.

On a full out war probably Noxus.

Azir empire is still rather small and even with sand soldiers at his command he would suffer from sheer numbers. It might be different in the long run especially if Susan and Xerath join him (in which case Shurima gets an easy win).

Ooooh boy here I go again. Ok Im gonna say that no outside intervention. Meaning no nation helping another nation and Xerath for some reason leaves Azir alone. The last info we had on Shurima was like 5 years ago with Bloodline (if you want I can exand why I know Bloodline was 5 years ago) so we can only make assumptions regarding Shurima's current army (and Azir's mortal army wasnt even featured in Bloodline so even more room for assumption). But based on info we have and most resonable assumptions: Noxus can't invade Shurima directly cause in desert Azir would stomp any army. Like, no joke. This guy is srsly op in the desert. It is basically his huge sandbox and he can manipulate the sand on a huge scale (while raising the capital back, he lifted millions of tons of sand), so he could bury Noxian armies into the ground alone with some huge sand tidal-like waves or shoot a rain of sandspears (similar to what his soldiers have, they are steel-hard btw and he made them from sand) at the enemies (this is a logical assumption cause we have seen him create spears from only sand, and he can control sand on a huge scale), or make huge sandstorms to kill the Noxian armies (Nasus's smaller version of it while he was weakened was said to be strong enough to reap a big camel-like creature to bone in minutes. Azir could create huge, much much bigger sandstorms that are even more deadly for a soldier. Even ignoring that Azir can solo whatever Noxus brings in Shurima, Shurima is mostly a desert with no water sources until you reach the main river and some cities. Shurimans have home field advantage if Noxus decides to invade them first, making it very easy to make ambush with camouflages or ram down the enemies while on the back of the Dormuns (Dormuns are fking huge btw). Azir also has some magical relics that have been around and survived since the fall of Shurima like Stone Golems (ex: the one in Ryze's cinematic) or those magical bombardament spheres that we have seen in Where Icathia Once Stood. Regarding the mortal army, Im not gonna make any big assumptions because we have simply didnt get to see them in action, but we know it would be mostly made from warriors from the tribe given military training and city guards/garrisons from other cities that existed before Azir's return. So with homefield advantage they should be able to hold Noxus at bay because they are accustomed with the land, fighting in the desert, and surviving in it, while Noxus's resources would grow thinner and thinner thanks to ambushes and guerilla attacks. Shurima also has Nasus, who is arguably the best strategist the world has ever seen, who besides being a military mastermind, can fight entire armies on his own too. Taking all that into account, Noxus would be cripply screwed if they attacked first cause many of their armies would be destroyed. They prob couldnt even bring their cavalry, like basilisks and horses, because they might die in the desert due to not being adapted to living there, so no warbeasts for them. The only advantages they would have in Shurima is numbers and intel due to Swain's demon who can scout the area. But, as I said, numbers wouldnt matter that much because of home field advantage and, if it really is needed, Azir can make ten thousand elite sand soldiers (they are made as a reflection to his 10.000 elite guards before the fall) or even more to even things up.

Now, Shurima can't invade either. Dormuns and Skallashi would most prob die too in Noxus because of not being adapted to it after a longer period of time (like a few weeks at most). The numbers do matter here much more as Shurimans wouldnt have the home field advantage, and Noxian fortresss are in general better fortified. Noxians on the other hand would have their full cavalry alongside their warmachines. Azir wouldnt be in the desert to be able to carry hard, and he couldnt ressuply his sand soldier army while in Noxus cause no sand. Shuriman's high chain of command (which I think will be mostly tribe leaders and city garison commanders besides Nasus) would be vulnerable to assasinations from Noxians. The slight edge in combat that Shurimans had due to being in their home land would be gone. Noxus also has atm an edge in magic if we exclude champions unless Nasus and Azir trained some mages already but this would be speculation so Im not gonna take that into account, therefore Noxus has an edge in magic too with their warmages and bloodmages.

So really, it depends who attacks first. The one who attacks first would be really crippled and thus much easier to invade by the one who was first attacked. So it really is gonna get down to who gets more impatient first.

Azir. Hands down.

Infinite soldiers and the Sun Disk

However, if everyone from Noxus was in the war, then we'd need every Shuriman, since Azir's Empre includes people such as Amumu, Nasus, Rammus, Renekton, Rengar, Sivir, Skarner, Taliyah, and Xerath.

Even then it'd be a stretch between 10 Shurimans and 16 Noxians / Noxian related people + their armies.

But with for people with Shuriman related connections, it'd be a 26 v 16, and this is because of people like Aatrox, who were former Ascended, and people like Kai'sa, since she was originally born in Shurima.

Piltover and zaun would probably be helping noxus, even if they don't join the war directly. This gives noxus things like chemical weapons and machine guns, which will make them hard to beat. However if they are on the offensive side (invading the desert) they will be at a disadvantage that their weapons may not be able to compensate for, and it would quickly become a war of attrition (think "don't invade Russia in the winter" but instead it's "don't invade shurima in the summer"). Also it's entirely possible that the void might step in, obviously not taking a side but void creatures would catch noxus off guard whereas shurimans have been dealing with them for quite some time. I think that a war between shurima and noxus would end in a stalemate like the current demacia vs noxus tension.

Noxus is probably already putting soldiers on their front lines in the territories they own in northern Shurima. You don't think the rumours of a once dead Empire coming back to life would put them on alert?

In this discussion, Azir wouldn't win but why would Azir risk his empire just to claim a few towns on a border. If Noxus feel Shurima a threat they may infact install help Xerath install his regime as long as Xerath afterwards keeps to his borders. Yet they might also not want to deal with a madman.

Azir has no help coming either, he's on his own. Other Ascended's don't care or are mad, other Shuriman don't care or are cursed and Taliyah would not go to war. Commanding a an army of soldiers who don't fatique doesn't mean Azir doesn't. Can he reliably remain safe at all times vs Noxus' full potential, that is not just an army of willing soldiers, many of whom are powerful but assassin's and alike?

Remember, Ascended's are not all powerful. Many have died, Azir will be no different.

This said, I doubt either side want a war when they have other issues. As long as Azir doesn't try and take those northern cities back, nothing will happen.