Knowing that you have one and a half gallons of magicka isn’t exactly enough for you to make a gauge out of it. You’d still need to know what total amount that is out of, and have some way to tell how much it’s changing by each time you cast a spell.
The first question, though, might have an easy solution. You direct your thoughts back to the skeleton and wonder how much magicka it would take before your tank is full.
The skeleton forewarns that it was not created to display magical aptitude, and only possesses the basic magical knowledge the Makers® have decreed necessary for client relations†. As it understands things, however, the question isn’t “how large your mana tank is”, but rather, “how much mana you can wield control over”. Have you ever siphoned power from a soul fissure?
No, you think in response.
Have you ever attempted to animate a nonstandard skeletal construct with more bones than the soul bound to it originally possessed?
No, I haven’t.
Have you ever used alteration spells to warp a larger area to fit within a smaller area of a different shape?
No, I don’t… think so, but will admit a degree of ambiguity on that one.
Well, storing mana for spellcasting is like any of those things you haven’t done. There is no maximum amount one can carry so much as there is a functional limit to what an individual can learn how to manipulate.
Oh! So it’s kind of like finding how much you can lift? You just have to keep picking up weights and see at what point you can’t do it?
The skeleton supposes so, though such an analogy seems unnecessarily abstract and difficult for CairnCorp®‘s clientele to relate to. If you would like to estimate the upper limit of your mana-wielding capabilities, the simplest route would be to gather or generate mana and take note of the point at which you can wield no more.
You can’t generate your own magicka, so doing a test like that isn’t exactly… easy for you, you admit.
Oh, right, you forgot you have money now. Everything is easy for you.
You splurge and drop 221 septims on the strongest magicka potion you can find. The skeleton informs you that you now have approximately seven and a quarter gallons of magicka. Nice.
You ask the skeleton if that’s a good amount for a mage to cap out at. It ponders the question for a minute, then explains that its etiquette training suggests an abrupt change in topic. How’s the weather on Nirn?
It’s… Nirny, you guess. You’d say “normal”, but the meaning of that might be lost across planes.
Before you go and blow a hundred septims worth of magicka on a summoning spell, you check with the skeleton as to whether there are any ways to bring the spell’s magicka cost lower. Like, are there… better ways to cast it? You’re already cleaning up the blue squiggle.
The skeleton tells you that the mana usage of star-tesseract-style conjuration predominantly comes down to the efficiency of the leyline. A straight line will be more efficient than the one used during your previous summon, but conjurers with more experience navigating the planar layout can typically forge a route shorter than a straight line. Routing through smaller planes helps.
You don’t suppose there’s a map available explaining the shortest route?
An nth-dimensional map such as that would be very difficult to portray in a two- or three-dimensional model. Celestial routing efficiency is typically‡ regarded as a skill conjurers pick up through experience. CairnCorp®‘s official stance is that conjuration technique is best improved through regular and repeated conjurations with CairnCorp®.
But like, we’re already telepathically communicating. Is there no way to just transfer the maps into my head?
It stresses that this is a front-level mental link through a long-distance leyline. What you are asking would require transferring a conjurer’s actual experiences navigating starmaps.
You said there were magical ways to shift experiences from one person to another, right? Is that something I could use here? Like, could I get a more experienced conjurer to use that experience-tampering magic you mentioned to show me how he-
Huh, maybe you should’ve actually read this book rather than just idly holding it that entire time. You didn’t even get a chance to take up the skeleton’s offer to connect you to Vaermina’s plane.
Though, if what it said about bi-hourly mind wipes is true, you guess you can just try again in half an hour.
Or two hours. It’s weird that ambiguity still exists telepathically.
…after you’re off the phone with your bone-friend. Probably best not to expose them to that.
The skeleton’s thoughts about restoration magic implied it might actually be able to make you better at other types of magic. If restoration magic is really that powerful, you doubt using it is as simple as thinking happy thoughts or believing in yourself.
Or eating a book about it.
As for Asotil, you’ve been giving the road regular checks and the most you’ve seen is a trapper carrying some rabbits. The sun is going down, though, so it’s pretty likely Asotil’s schedule was shifted six hours forward and he’ll show up in a couple hours.
Speaking of, are there any ways for us to regain mana right now?
You… guess if you have a full tank of magic, a temporary block on summoning, and no apparent route forward with restoration, it’s time to try the lightning spell.
You doubt you’ll have time to get much of a handle on it before Asotil shows up like he said he would, but… yeah.