A deficiency of prana in the atmosphere.
To be honest, losing communication with Chaldea due to a lack of magical energy isn't that much of a penalty for me. In the first place, Chaldea's scanning capabilities—except for special circumstances like Oceanos—were almost always a step behind in every situation. It's also more sensible for Roman and Olga Marie to focus their resources, including communication, on the Team A Masters who moved to the Fuyuki Singularity and on Ritsuka, unless it's a truly dire emergency…
However, the real problem is that the lack of prana isn't a penalty on the level of just a temporary disconnection from Chaldea.
No matter how much I claim to dislike magi and talk down to them, in the end, if you set aside the Rinnegan, I am nothing more than a mere magus—or rather, a spellcaster—who learned magecraft from the Witch of Fairy Tales, and the 'Magi' Aoko Aozaki and Touko Aozaki. In the magnificent scenes of havoc I've wreaked so far, the ocular powers of the Rinnegan have always played the lead role.
The Soul Extraction of the Human Path, which suppressed Lugh Beowulf and turned me into a fake Third Magician; the Deva Path's Chibaku Tensei and Shinra Tensei, which have now become my identity; the Naraka Path, which I use so effectively for repairing Mystic Codes; and the Animal Path, specialized for wars of attrition… Excluding the Outer Path techniques I've never used, the techniques of the Six Paths have all been lifelines that saved my skin at least once.
But as they say, there is no power in this world without risk… My Rinnegan's ocular powers possess one fatal flaw. It is the extreme consumption of prana.
Back in Fuyuki, when my Magic Circuits weren't yet fully formed, simply using Chibaku Tensei once almost killed me as my circuits overheated. When I used Heavenly Obstruction at the Clock Tower, I pushed myself a bit to ensure I wasn't looked down upon, but my circuits were significantly overheated then as well.
If it weren't for the method of absorbing the prana of the Fifth Magic via Seal Absorption with the support of Aoko-neesan, I probably would have died from prana depletion. However, after becoming somewhat accustomed to the Rinnegan's ocular powers—that is, after reaching adulthood and becoming familiar with the techniques of the Six Paths—I could use various techniques even without such backup.
The reason is simple. Just as I normally wrap myself in Shinra Tensei on semi-auto for defense or use the Rinnegan for prana detection as a passive ability, I also run another Rinnegan technique, Seal Absorption… the absorption of prana, as a near-passive.
I got a rough feel for it during the fight with Archetype Earth, absorbing the ether dissolved in the lunar atmosphere which was close to the Age of Gods. Through individual practice with Aoko-neesan, I learned how to absorb prana even in situations that weren't overflowing with it like the Age of Gods or the Moon.
The reason I could drop a Heavenly Obstruction on the Rail Zeppelin without any particular support was thanks to absorbing prana from the atmosphere, which had been enriched by the rampaging Dead Apostles through Seal Absorption. The reason I could spam the Tsar Bomba or various Six Paths techniques from the First Singularity onward also ultimately stems from the prana absorption of the Preta Path… Though my Magic Circuits themselves are high quality because of the Rinnegan, unless there's a magical reactor like the Holy Grail, the amount of prana my physical body produces on its own is bound to be low. I simply sustain a cycle by constantly replenishing and spending…
"…This isn't good."
"Is it dangerous, Master?"
"Dangerous… Yeah. To be honest, it's incredibly dangerous."
Frankly speaking, my current combat power is lower than it was during the Fourth Holy Grail War. At least back then, Aoko-neesan was attached as support… Absorbing and using Altera's prana is also out of the question. Her physical body is composed of prana, an undead state where prana is constantly supplied and regenerated, but if I were to absorb her prana, Altera's body wouldn't just regenerate after being destroyed; it would 'vanish.' It's a concept of reducing the total HP bar rather than just decreasing the HP gauge… Simply put, even with something like Impure World Resurrection, it would inflict a wound that cannot be regenerated.
The Deva Path has good prana efficiency and is practically my only means of defense, so I can use it. However, using Chibaku Tensei or Heavenly Obstruction is impossible. It wouldn't be an exaggeration to say my total power is drastically reduced just by that…
"The Animal Path is also essentially sealed… It's a shame to lose an effective means of reconnaissance."
In a situation where prana is lacking and replenishment is difficult, using summoning arts is a suicidal act.
The same goes for the Naraka Path… Just in case, I brought Francesca along inside the Naraka Path as a reserve, but if I were to release her in a prana-starved state, that crazy hedonist would try to kill me regardless of the Singularity.
The Asura Path is… well, obviously out of the question. At least the Animal Path returns a certain amount of prana when the summons are released, but the Asura Path is truly a prana-eating hippo. Prana is consumed just for simple physical reinforcement, and when it comes to transforming the body into a weapon… well, the level is astronomical.
"…Whew, whining about it won't change anything. Altera, let's move first."
"Understood. The method?"
"Normally I'd summon a Nue or an ostrich to ride… but now isn't the time to use something like that."
I pulled out a Mystic Code that Ritsuka had rolled, just in case.
I gave most of the Mystic Codes to Ritsuka's side, but fortunately, I took a few of the duplicates for myself. Not the Magdalene's Holy Shroud from a summoning rite, but the authentic Magdalene's Holy Shroud officially loaned from Caren, the Black Keys provided by the Holy Church… and the 'Ho-tobby,' known as the Motored Cuirassier.
"We'll move on this… Altera, it would be best for you to ride in the sidecar Da Vinci made."
"I understand."
It's true that Altera has the Riding skill… but this Ho-tobby is strictly a motorcycle, a peak of human civilization. Its compatibility with Altera is the worst; having her drive would not be a wise choice.
"Then… let's go. Let's see just what kind of mess is unfolding in this Singularity."
*
We race across the wilderness, kicking up clouds of dust.
The wasteland where not a single blade of grass grows continues endlessly. At this point, I'm genuinely confused if I'm in a Singularity or if I've dropped into the Land of Steel timeline. Just in case, I checked our location with a compass and magecraft activated with what little prana I had; this was indeed near Denver, Colorado, in the United States.
"…By now, it would be normal to encounter a Servant, whoever it may be… It's better to meet someone, whether ally or foe."
In a situation where there's only Altera and me, it's wiser to even encounter an enemy. If I lose, that's the end, but I have the confidence to escape, and I can just extract information from the enemy I encounter. But… if there's nothing, there's no answer other than moving endlessly. Truly, this was the first time I've missed Chaldea's scanning technology so much. Is the only silver lining that the Motored Cuirassier is a Mystic Code, so it won't overheat or be destroyed?
And at that moment, though its function as an Ocular Spell was almost meaningless due to the prana deficiency, my Rinnegan—still retaining its value as eyes of insight—quickly caught a 'human shadow' nearby.
Shabby attire and a clumsy gait… they weren't just refugees, but almost wandering beggars. These people, who looked in worse condition than the kotjebi in North Korea from my previous life, possessed a quite vicious aura despite their emaciated appearance.
"…Enemies?"
"Don't kill them for now, since we need to interrogate them. We have enough food… it wouldn't be bad to trade it for information."
Bringing the Ho-tobby to a halt and leaping onto the cracked earth, the people walking through the wasteland, where heat haze rose due to the scorching sun, began to come clearly into view.
As I saw before, they seemed to have lost a significant amount of weight from starving for a very long time, and they appeared to be holding crude bladed weapons… but…
"…Firearms… and modern ones at that. Were they refugees from the President King's side?"
Thomas Edison in the 5th Singularity was possessed by an obsession because of the Heroic Spirit components of past American presidents that were forced upon him, and the fact that his invention and mass-production capabilities were falling behind the Celts. He was planning to turn this Singularity into a Lostbelt-like state by modifying citizens into mechanical soldiers.
Fortunately, after being hit by Nightingale's corrective punch and listening to her lecture, he would eventually come to help as a proper 'supporter'… but…
"Wait, the prana flow is strange… they're mechanical soldiers?"
It was hard to say their entire bodies were modified, but I could catch a foreign prana near their arms, legs, joints, various organs, and around their eyes. Although infinitely lacking, it was an aura similar to the puppets Touko-san made, or the prosthetic arms and legs crafted by Da Vinci… though the performance was much lower since they were mass-produced models.
"…It seems they're defeated soldiers. Tsk, food is limited… and we can't get supplies from Chaldea. This is difficult in many ways."
And at that moment, the people who appeared to be exhausted defeated soldiers or deserters also noticed me. They came running while dripping with sweat and surrounded Altera and me. Holding crude blades and firearms that looked decent on the outside but were rusted, they began to threaten us, pointing them our way.
"H-hand over everything you have!"
"That strange thing from before… that vehicle, and hand over that woman too!"
"Hmm… and why should I?"
"Shut up! Can't you see this gun!"
Rat-tat-tat.
Three bullets were fired toward the ground, and they all brandished their weapons threateningly or pointed them at us.
"Decide quickly…"
"Sigh, fine. First, I should hear your story. Just sit down. You clearly look hungry."
"What?"
"I said, sit."
I'm in a position where I must rely on natural recovery since I can't absorb prana, but I can easily suppress a few incompletely modified mechanical soldiers.
Forcing them onto their knees using Bansho Ten'in, I took out a ration and a nutrition bar stored not in the Naraka Path, but in the subspace within the Mystic Code.
"F-food!"
"Give it here, no, please, just one! Please give us just one!"
"Ah, you can't have this… no, I'm not saying I won't give you food, but you've been starving for quite a while, haven't you? You lot. If a person in a state of starvation suddenly eats food, it puts a strain on the internal organs, especially the liver. It's better to soothe the stomach with something simple like thin rice water or porridge first. I'll give you some supplements and water for now, so take these!"
Fortunately, although atmospheric prana was lacking, moisture itself existed normally. Using water magecraft to gather moisture and create water, I handed a glass to each of them and simultaneously passed over a few supplements. Since the calorie count is overwhelmingly insufficient, it's impossible to satisfy their hunger right now, but at least it won't put a fatal strain on their organs.
"T-thank you… thank you! Ev-even if it's just water, thank you so much!"
"…You seem to have starved quite a bit… By the way, is there no water around here?"
"The last time we found water was two weeks ago… we filled our canteens then, but they ran dry long ago."
"Since the world is a mess, it's only natural for deserters to suffer… So, are you all troops from the President King… Edison's side?"
"…How did you… no, it would be stranger if you didn't know. Considering my body is in this state."
The man who appeared to be the representative spoke self-deprecatingly while shaking his arm, which had been modified like a machine.
It was clear his feelings toward Edison weren't pleasant.
"It's obvious you were troops on the President King's side. Can you tell me anything about the current situation? I've been riding through the wilderness for days and I can't see the end of it."
"…Excuse me, but how much do you know about this situation?"
"Just, well… roughly that the President King and the Celtic forces are having a go at each other?"
"You must be from a countryside where news doesn't reach, or you've come from a very distant place. The President King's forces have already been annihilated."
…What?
"It's a story from two months ago… The President King's forces were recording defeat after defeat against the Celtic Mad King's army. They planned a grand operation to attack Washington all at once as a final gambit, but the Celts' strongest, the Mad King himself, stepped forth and personally annihilated all of President King Edison's main forces and seized the entire United States."
"Wait a minute… then what happened to Edison?"
"…He was beheaded along with his advisor, Helena Blavatsky, and their heads were paraded around. Fortunately, the Commander-in-Chief, Karna, managed to escape and join the resistance while the two Servants bought time, but the resistance also took a significant hit from Medb's special attack forces and has gone into hiding."
"Then you lot…"
"…Are the defeated soldiers who barely escaped the final battlefield with our lives… yes."
…The situation is worse than I thought… no, wait a minute.
"Then, how long has it been since the President King's forces were completely defeated?"
"…It's been about two months."
"Second Magician have mercy…"
Two months.
After clearing out even the last resistance force of the President King, that's plenty of time to seize the ley lines of the entire United States…
"The commanders on the Celtic side… they'd be Queen Medb and the Mad King, right?"
"Yes, that is certain."
"This is not good… not good at all."
Medb and the Mad King, Cu Chulainn, have no particular goal. It is simply to destroy and rebuild the land for a violent Ulster. The Mad King is the crystallisation of the 'Cu Chulainn she desired,' perfected by Medb, and the violent Cu Chulainn moves according to Medb's will.
If I had to pick a similar target… yeah, Gilles de Rais fits Medb's goal the most. Materializing the Jeanne d'Arc he desired, the Cu Chulainn she desired, to complete the ideal world they want.
In Gilles de Rais's case, it was revenge against France, and for Medb, it is to build and live in a Celtic Empire.
Furthermore, considering the current situation, Medb has effectively swallowed the broadly spread ley lines of the United States whole… That output far exceeds the output of any Holy Grails we've encountered so far… perhaps it even exceeds the 'Mud' of Fuyuki's Greater Grail from the Fourth Holy Grail War.
"Alright, last question. Where is the resistance now?"
"…I don't know that. I am merely a defeated soldier… This information is also from two months ago, so I cannot guarantee its accuracy."
"Ah, dammit… this is truly a headache. Then just tell me where the Celtic camp's headquarters is. You can do that much, right?"
"If they haven't moved the location of their base, the Celtic headquarters should still be located in Washington… since all of the President King's forces marched on Washington under the pretext of driving out the capital."
"Phew… alright, thank you for the information. This is your payment."
Using water magecraft to generate water to the limit of what I could create, I filled their canteens as much as possible, handed over a few types of food with the lowest calories among what I had, and gave a warning.
"I can't give you any more than this for now. Leaving aside the fact that I need to survive too, I only have combat rations or high-calorie foods. If you lot eat this now, you'll die of multiple organ failure or bacterial infections."
"…Just providing water is more than we deserve. Thank you so much!"
"Haha, it would be nice if I could always receive such gratitude."
The group of defeated soldiers swallowed the tablets I gave them one last time before they started walking back in the direction they had come from. I turned the Ho-tobby around and said,
"Altera, we need to head toward Washington first… My detection abilities are quite low right now, so if an attack comes, respond with whatever you need to, 'without killing' them. Got it?"
"Understood."
"…Sigh, it's like talking to a robot."
Well, maybe she really is a robot… considering the true Altera—the Machine God Velber.
In any case, to think several months have already passed in the Singularity. Just what on earth is going on here?
"Whatever it is, I just hope it's not on the level of the Third Singularity…!"
Full of anxiety, I slammed my foot on the motorcycle's accelerator.
*
"He's coming."
"Hmm? Cu-chan~! What's coming? Ah-ha! Don't tell me you want to do it again? Cu-chan, you're so greedy!"
"It's not that, Medb. It means someone worth fighting is coming."
"…Hmm? Well, haha! Are you talking about those people from the observatory? You're not seriously believing what that weird electricity-man said, are you, Cu-chan?"
"I believe him. The President King I beheaded back then was weak and his eyes were dead, but Nikola Tesla, who was in the resistance, was a man worth remembering. Yes, if it's someone who can stay in that man's memory, they must surely be someone worth fighting even for me."
The figure laughing with a wicked smile… looked more like a warrior than a king.
Medb also knew that fact. The Mad King Cu Chulainn, the Tyrant Cu Chulainn—the one who created him was, naturally, Medb herself… but that didn't mean she disliked Cu Chulainn as a warrior.
An Ulsterman is naturally a warrior, and a warrior is naturally an Ulsterman! The Celtic Empire, the cruel and atrocious empire of evil!
The king of that place, the greatest warrior of that place, the Demon King of evil and the strongest warrior, Cu Chulainn. That was the existence created because Medb desired it.
"Then it's settled, isn't it? Our empire doesn't need an observatory!"
"Yeah, of course. Even so, according to Nikola Tesla, he's a person who has already broken through four Singularities… it would be boring to face such a warrior merely as a king."
Picking up the Spear of Piercing Death, Gae Bolg, he made a confident declaration.
"The moment he arrives in Washington, I will face him. Don't you interfere, Medb. Deal with the other Servants by his side… This is a one-on-one duel between the Master of Chaldea and the warrior of Ulster, Cu Chulainn. I will bring victory to you—a thorough, absolute victory!"
"Ah, yes. That's it, Cu-chan. That's the Cu-chan I want. Yes, as a warrior of evil, as my strongest warrior, bring me victory!"
Medb laughed.
Gazing down as she stepped upon the scenery of Washington—a paradise where lush green trees were fresh and milk and honey flowed—Medb cried out with a smile bordering on madness.