They say bad premonitions always come true, and sure enough, this was no exception.
Our forces' operational plan went wrong from the very start. The reason was laughably simple. Commander Barbatos's predictions had all been correct — they'd just been *too* correct. Fog. An absurdly thick blanket of fog had settled over the entire Austerlitz region. It had begun rolling in during the late evening and, as it turned out, would not lift for a full twelve hours, persisting all the way until noon the next day.
"……Hmm. We won't even be able to see the enemy when they're right on top of us."
Laura voiced her concern. She was right.
The battlefield's visibility plummeted in an instant. The fog reached its peak in the dead of dawn. You couldn't see more than a hundred meters ahead. In the worst spots, visibility dropped to under fifty meters. I could have excused myself, wandered off to the other side, and had a nice little rendezvous with Laura, and not a single soul among our ranks would have noticed — …no, that wasn't to say I had any particular intention of doing that. Both Laura and I possessed fully functional brains when it came to reading time and place.
A hundred meters of visibility. This was serious. For a knight order, a hundred meters was nothing. They could cover that distance in the blink of an eye on horseback.
If we weren't careful, we'd be caught completely exposed in the path of the knights' charge. A cavalry charge was something you could barely hold off even with thorough preparations — and we hadn't prepared at all. Just imagining it was terrifying. Naturally, the Demon Lords were consumed by unease.
Commander Zepar stepped forward to explain the situation himself. And the reason for this near-unnatural phenomenon was quite the spectacle. I was so dumbfounded I had to ask him to repeat himself.
"I'm sorry? Did you say the spell *failed*?"
"To be more precise, it succeeded too well."
Here's how it happened.
Commander Barbatos had worried that the fog around Austerlitz might not be thick enough, so starting six days before the main advance, he'd taken precautions. He ordered the military mage unit to cast weather-manipulation spells.
Each Demon Lord had a handful of mages under their command — two or three per lord. When the Sixth Legion pooled every last mage, they'd assembled a corps of roughly fifty. Thirty of them were high-ranking mages of the third Circle or above. They had arrived at the lakes around Austerlitz well in advance and spent six full days artificially manipulating the weather. And then……the mages had been *too* competent, turning the entire surrounding region into a swamp of fog.
"Apparently Commander Barbatos himself was caught off guard."
"Well, can you blame him? This is a bit much, isn't it?"
"A few of the mages got overexcited and went off the rails on their own — personal curiosity and whatnot."
Commander Zepar stroked his mustache.
"Given how rarely they get conditions suited to large-scale weather magic, they couldn't contain themselves."
"……Hah."
A sigh escaped me before I could stop it. Mages were truly a species ill-suited for the battlefield. No matter how much disciplinary training you put them through, mages always prioritized the individual over the group. The reason they threw themselves eagerly into battle wasn't to secure victory for their allies—it was so they could put their magic through its paces. And when you gathered fifty of those oddballs in one place, you could well imagine what would happen.
According to Commander Zepar, the mage unit had strutted around Barbatos wearing expressions that practically screamed, "We did great, didn't we? Didn't we? Now praise us!" with absolutely no idea what they'd done. Barbatos blowing up at them was only natural. But he couldn't very well discard high-value combat assets like mages on the eve of a battle, so he'd supposedly just stomped around seething with nowhere to direct his fury. Poor man.
I spoke, harboring a small hope.
"Wouldn't the operation change, brother?"
"I was hoping for that myself… but the Legion Commander is a man of very strong convictions, so who knows. Let's contact headquarters first."
"A battlefield with limited visibility favors the attacker over the defender. When neither side can get a read on the other, whoever moves first seizes the initiative. If we hand the right to attack over to the Imperial Army, we'll have no choice but to be dragged along by their movements."
Commander Zepar nodded. It was common sense of the most elementary kind. In anything other than a siege, the attacker held the advantage over the defender. The attacker could strike where and when they pleased, while the defender could only respond after the blow fell. Barbatos, who had been rolling around on battlefields for two thousand years, could not possibly have been ignorant of that fact.
"His Excellency has returned."
But my hopes were dashed almost immediately.
"The Legion Commander has ordered the operation to proceed as planned. Our right flank will enter defensive posture as is."
"But Lord Zepar."
One of the Demon Lords who had newly joined spoke up.
"I worry whether we can even coordinate properly among ourselves like this. We need to establish a defensive line, and we can't all just cozy up in the command post together. Each of us must hold our assigned sector and intercept the enemy in a coordinated fashion. But with the fog this stubborn, allied cooperation is going to be next to impossible."
I privately agreed with the assessment.
If I were the enemy commander, I would employ a feint attack. Launch a main force assault against our right flank. While the right flank was caught up in a desperate fight, I would use the knights as a spearhead to pierce through a section of their formation in a single thrust. With the fog this dense, moving the knights into position would be easy enough. The knights would break through the formation in an instant, then immediately wheel around and coordinate with the main force to crush our right flank from both sides. A simple yet effective tactic.
To prevent such a disaster, coordination and communication among allies had to function flawlessly above all else. You needed to know at all times which positions were under how much pressure, which allied units had moved where, and if a section of the formation was pierced through in a single instant, exactly where that breach was.
"Your concerns are legitimate. But worry not. The Legion Commander has dispatched a mage posthaste for the purpose of allied coordination."
"The mage unit, you mean?"
"No. A single one."
It was baffling. Not an entire unit, but one mage—how was a single mage going to solve the communication problem? Were they perhaps planning to conjure up a wind spell and blow the fog away?
"The mages are responsible for organic communication not just within our right flank, but across the entire allied force. Each Demon Lord will be assigned one familiar raised by a mage. When you have something to report to your unit, use the familiar to relay it immediately."
"I'm sorry. I don't quite understand."
Rank 58, Amy, spoke up cautiously. She had earned the right to speak after her contributions in the Black Mountains campaign, but she was still a newcomer and held herself in check. Then again, even if she weren't a rookie, it wouldn't be easy to speak freely in front of Rank 16, Zepar. Even the mid-ranking Demon Lords of the Plains Faction used half-honorifics when addressing him.
"So how exactly does the reporting work?"
"You report to your familiar. The report is then instantly relayed to the mage who shares a mental link with the familiar. From there, the mage acts as a relay and forwards the report to other units. The mages remain positioned with their respective formations, and orders are also issued in real time through the mages' familiars."
"Oh, so that's how it works."
Amy exclaimed in admiration. I felt the same way. So the familiars served as radios, and the mages served as relay stations! It was less convenient than the radios of my original world in that it required an extra hop, but this was far from nothing. If anything, the higher-ups could always stay informed about the front line's situation, which might actually prove to be an advantage.
As I was marvelling anew at the strategic value of mages, Commander Zepar upped the ante.
"Furthermore, three hundred Demon Birds will be released over the battlefield. You will be able to observe the battlefield more freely through the Demon Birds. Not only you, but the mages will also deploy their familiars for reconnaissance."
I immediately grasped what Commander Zepar meant. They were leveraging the Demon Lords' ability to read monsters' emotions. If the Imperial Army attempted a flanking maneuver or a single-point breakthrough, the monster birds positioned overhead would detect it and raise an alarm. The warning would be relayed to the Demon Lord at once. It functioned as a kind of early-warning system.
The fog was thick, so the birds wouldn't be able to survey the entire battlefield, but it was obviously far better than nothing—hundreds of times better. The possibility of being blindsided by the enemy because of the fog had been drastically reduced.
Maybe this would actually turn out to be a rather favorable situation for our side. Had the human army prepared countermeasures of this caliber for the fog? If not, Austerlitz would become a vast grey tomb for the Imperial Army. When the meeting concluded, Laura whispered in an excited voice.
"My lord, this is a groundbreaking approach!"
I agreed with her. Not long after, a familiar was distributed to every Demon Lord in the right flank, myself included. The familiar, surprisingly, was a slime. This small monster, composed of blue viscous matter, latched itself snugly onto the back of my neck. The only difference from an ordinary slime was what appeared to be a mouth-like organ.
I decided to give the slime communication a try.
"This is the Dantalion unit. No issues on the front line."
A few seconds later, a mechanical voice leaked from the slime's tiny mouth.
"This is right-flank command. Understood. Not just you—all commanders are diligently reporting that there are no issues on the front line. From now on, only report significant matters."
I smirked. So I wasn't the only one testing out the slime communication system. The other Demon Lords were probably using it too, under one pretext or another. Commander Zepar must be getting fed up by now with replying to every single Demon Lord one by one.
Laura, who had been eavesdropping on the exchange from beside me, spoke up. "The Imperial Army could never use a method like this."
"Hm? Wouldn't it be possible if they used mages too?"
"The problem is the familiars. What level of intelligence could a familiar have to understand reports and relay them? You'd either need to produce extremely high-quality familiars, or have a mage concentrate on a single familiar to achieve complete mental synchronization. Either way, it's not a method suited for large-scale communication. If there was a mage attached to every unit, maybe — but that's out of the question."
She smiled.
"For the Demon Lord, all those steps are bypassed. He projects mental images and commands directly to his monsters. In effect, those images pass right through to the mages themselves, skipping a step entirely. Now I understand the Corps Commander's intentions... a fog-shrouded battlefield is unquestionably advantageous to the Demon Lord's army."
Laura's explanation went like this. The Imperial Army lacked proper authority in its command structure, and there was friction between the Central Army and the Border Army. On a battlefield like Austerlitz, where visibility was extremely limited, the discretion of field commanders could only grow. When the enemy might burst through the fog and appear a hundred meters away at any moment, who had time to wait for orders from higher command?
Even if Margrave von Rosenberg issued orders as Commander-in-Chief, the commanders would have justification to say, "I'm sorry, but we acted on our own initiative based on the situation on the ground." The Supreme Command had no way to know the actual conditions in real time anyway, so they'd have no choice but to accept the commanders' independent actions.
In a situation where even justification was in place, would twenty thousand Central Army troops and twenty thousand mercenaries obediently follow the Supreme Command's orders? They would inevitably act on their own at the drop of a hat, hiding behind the excuse that "the situation on the ground is different." The very existence of the Supreme Command would become meaningless. The Imperial Army would split apart. Meanwhile, our Sixth Corps had established an airtight communication and reconnaissance system. I looked forward to seeing just how decisive this difference would prove in actual combat.
A day passed for both the Imperial Army and the Demon Lord's army. The Imperial Army set up camp centered on the Pratzen Heights, while the Demon Lord's army devised and refined countermeasures for the fog. The first day of the two armies facing each other passed quietly like that.
And the next day.
Around five in the morning, the Imperial Army launched their attack. It was an attack we hadn't anticipated. The method was particularly unusual.
The ground suddenly rumbled — boom, boom — and jolted me awake. I rushed out of the tent, but it was dark and the fog had rolled in, so I had no idea what was going on. They must have distributed the slimes for exactly this kind of situation. I asked Commander Zepar what kind of attack was underway.
─ Hold on. I'm assessing the situation myself.
I waited patiently. Before long, Laura had come out of her tent too. Even as we stood there, the boom, boom sounds continued to echo from beyond the fog. Was one of our units under attack? What kind of attack could produce sounds that carried this far? Tense minutes passed.
A short while later, the slime's communication opening activated. Commander Zepar's message left me stunned.
─ Informing all units. The source of the booming is catapults. Repeat — the source of the booming is catapults. The Imperial Army has deployed dozens of siege weapons and is raining rocks in every direction.