What the heck is wrong with it? The runes behave very differently than the heat version, but why? Hmm... mhmmm...
He kept the other 8 runes by his side, and conjured the fire ray construct in his mental sandbox one more time.
The mana flows into it, the rune activates... And then it glows red. As it should be. But why?!
He scratched his chin and tilted his head back slightly to look at the rough stone of the cave ceiling. The ceiling was the only thing on the second level of the dungeon that was rough, while the walls and floors looked polished, even though they were also made of natural stone.
When the group first found such unnaturally smoothly polished rooms, they first thought they had stumbled into a secret lair of a criminal gang or the like, but had quickly changed their minds upon encountering the first red wolves.
The boss room, in which the adventurer team now camped, still had similarities to a naturally occurring stone cave, but at the same time seemed so unnatural, as if someone had manually ground away all the grooves and protruding stones.
Avan focused again on his current problem, while he considered the uneven ceiling and wandered along it with his eyes.
Small stalagtites and grooves ran through the rock, and here and there a few cracks could be seen in the descending rock formations, as if the stalagtites would fall down sometime during the next quake or something similar.
A small crack above Avan caught his attention for some reason, and it almost looked like a splitting lightning bolt that forked and zigzagged further.
Hmm... What am I missing?
Just as he was about to avert his gaze, it clicked and he noticed it like a perfectly fitting puzzle piece.

Of course! I'm an idiot, the obvious again not considered. Simply fail... With an embarrassed shake of his head, he turned his gaze back inward.
Only with an exit for the rune does anything happen at all... Man, I'm stupid.

He placed the rune he knew behind one of the others he happened to grab and again infused imaginary mana.
The rune glowed blue, and only when Avan placed another mana strand at the other end to draw off the contents, did the color change to a bright white, which also stood out white on the mana strand ending behind it, until not even a second later the construct seemed to fray.
Hmm... ok, the first reaction!

He placed a rune behind the new construct to push off, and watched again as the rune changed from blue to white, and then moved behind it in a pulsing bright white into the next rune, to be shot out with a single whoosh.
Avan was about to give a joyful yelp with his fist extended upward, when he pulled himself together quickly enough and gave another sigh instead.
"Are you okay, Avan? You're sighing a lot right now." Dani asked him with raised eyebrows, and by now had moved Patris to the floor so he could slobber on his own sleeping mat instead of her shoulder while she slept. Jen was rummaging around in her backpack, a delighted grin on her face as she triumphantly brought out a comb and began to tackle some of her pesky knots in her hair while humming a soft tune to herself.
A quick nod, as he didn't want to be distracted to continue testing, and Avan had closed his eyes again.
Well, what exactly was shot down? It saw like a shock wave. So... Pressure. Or air. Or gravity? Phew... could be almost anything that might create an invisible pressure wave.

Although he trusted his comrades, he did not want to reveal that he had directly learned more runes and save himself the questions or lies on his part, so he created the rune construct on the level above them, where he could just reach with his sphere of influence. 
The construct first glowed blue, and within less than the blink of an eye, created a blast wave that would have at least staggered any adult, or even had enough oomph to knock someone careless over.
Satisfied with his first test result, he immediately conjured another, and this time watched more closely to see exactly what it was that shot out and what it looked like.
It saw like... Pressure, right? Simple force directed outward. So, force? Force rune. I'll call it that for now... But what was the rune in Akkalon's dungeon for? Did the entrance have a defense mechanism, or is this some kind of force field?
So if I could create a shield, or a barrier in whatever form, that would be pretty awesome... Maybe there are others of the runes that are there for pure modifications? Like an exception rune or something. 
Besides being happy to play around with the runes, Avan didn't notice the others going to sleep and Linob running around placing wardstones in front of the entrances and exits of the boss room.
Avan tried the other runes, and stumbled across two more that worked, and five others that didn't work in the same constellation as the others.
One air rune and one mana rune, the former producing a significant wind blast and the latter simply sending mana in an aggressive form of a magic pulse.

The other five runes, however, just wouldn't work until he switched the position in the construct and put the heat rune in front, and one of the other non-functioning ones behind it. Four of them had no effect at all, except that the heat built up and exploded, of course only in his immanent rune sandbox.
But the other rune, for whatever reason, had exactly the remarkable effect that Avan had wanted before; it created a bubble around the point of origin!
The heat rune, depending on the size and amount of heat pumped into it and of course the size of the bubble rune, created a fiery shield around it. The shield, as Avan tested it on the floor above, hissingly burned the blood moss and other smaller creepy-crawlies effortlessly, but cost a tick more mana for each interaction, depending on the size and durability of the burned object or creature. 
The air rune created an almost transparent shield of moving air, which shredded and was probably super against arrows or the like, so could cut things with tiny air blades or deflect them away, while the power rune itself simply created a completely invisible shield all around, but which seemed to let gases and air through, but bounced magical or physical objects off, eating more or less mana each time depending on the force.
And so Avan had discovered his first rough variant of a magic shield and even apparently developed it himself, whereby he was sure that these rune formations, as simple as they were, could certainly be found on many enchantments and items.
He put the other four runes aside for the time being, until he got to know more runes and had more variations and chain links to experiment with. 
A glance at his celestial storage showed him that he had another 33 runes carved on small sticks, and with a brief inconspicuous glance around, he pulled the bundle of small sticks out of his backpack and sat down so that Linob could only see his back, all camouflaged to put his limbs in a more comfortable position.
A few minutes of staring later, 33 more runes of varying design and complexity floated around his sandbox and he went through the same tests in quick succession as before.
With a tingle in his stomach, he was testing rune number 16, and couldn't help a big internal grin when it turned out to be a suction rune. When he placed a heat rune behind it, he felt more as he saw the temperature in the imaginary room drop slowly at first and then faster and faster, while the heat rune didn't light up at all at first and then changed from a yellow to a dark red, only to explode from all the pent-up energy.
I can build a magical climate system! Send heat out with mana, suck heat from the environment! Ahahahaha how awesome!
A little inner dance of joy later, and several possibilities immediately floated around in his head, especially concerning the 2678 [Small Purple Mana Crystal] and 313 [Unique Purple Mana Crystal], which he could convert to batteries through enchantments, if he could learn that too.
But since he could only test runes in the sandbox, sooner or later he would have to sacrifice some of the small mana crystals until he figured out a working concept. But all that could wait, because he still had more runes in front of him, which wanted to be tested!

He found one more rune, and it converted blue mana into celestial mana, wondering why he needed it when his sphere of influence itself was processing and converting alien mana under his watch. In the battle in the city of Cyntha, he had observed how various strands of mana from the people around him had migrated to him, only to be processed and purified by him and sent back again. Higher concentrated, and without impurities, which removed unhealthy influences from it.
The rune would perhaps make sense when he himself was not around to purify mana, as on enchantments on items or even buildings. Or maybe... to cleanse that black slimy corruption mass? Huh... 

The other 31 runes, however, presented Avan with some other problems, as he could not figure out in which order they belonged and what they did exactly.
With a recurring sigh, he opened his eyes, feeling more than satisfied with his progress, and stretched his legs, bent until just now, toward the glowing remains of the campfire.
"I guess I should go to sleep, too..." 
With a quick glance and nod to Linob, who must have been taking over the watch, Avan was about to lie down in his spread-out sleeping roll when he noticed the wardstones for the first time.
What...? What is that? Curious and curious, but already lying in his sleep roll with his eyes closed, he let his feelers of the sphere of influence extend and took a closer look at the small, softly blue shimmering stones.

He felt his way along the fist-sized stone, and noticed the magical nature of the stone, which turned out to be [mana stone]. On the surface of the gem, for that is what the stone appeared to be when the translucent material inside was discovered, were a few interconnected runes.
He recognized two of them immediately, the force and mana runes. The mana rune sent mana from inside the stone, which was full of shimmering and swirling mana, into the force rune, which was connected to another rune with odd strokes on the side. 
Only when he had analyzed the other wardstones at both passages, he noticed a difference between the four stones. The two at the exit, in the direction of the stairs to the next level, had only a small line on the last rune, while the two wardstones to the left and right of the entrance had two lines.
That would mean... the stones are somehow - connected with each other? Do the strokes symbolize who they are supposed to connect to, to generate some kind of force field? But I don't see a rune for a field, or a bubble or something.... Is this maybe just some kind of tripping trap? But that wouldn't do much good would it?! Except that you can hear when someone touches the strand of force mana, because it bounces off. But what kind of poor defense is that?!
Just as he was about to curse further, he changed his view, and realized that the mana rune together with the force rune formed a billowing connection, instead of a straight tripping trap. This meant that Avan could see the mana strand alternating between the two paired mana stones directly stretched and a loose arc, completely random and without a fixed pattern.
Anyone with any kind of mana vision can see that right away! You just have to wait until the connection on the ground is briefly tense, and then step over it before it changes back into an arc. How retarded is that, please?
Shaking his head and slightly frustrated, Avan set his own sphere of influence back to maximum concentration in the immediate vicinity, so that he would be able to hear even in his sleep if anyone approached the cave or even himself.
On the one hand, somehow pleased to have seen the construction and memorized the rune of the connection, which had actually been one of the unknown runes in his lexicon, but on the other hand, frustrated at how shoddily made these wardstones seemed to be.
With these thoughts, he fell into a light sleep.

He woke up the next morning, when the others started to prepare breakfast and were just making tea, with tired eyes.
Yes, well - it was not so smart to stay awake so long and to play with the runes... But anyway!
After the group had polished off another tea and some of the dried rations, they carefully descended the stairs, which seemed more and more artificial the further they descended.
"Watch out! Whatever is down there has intelligence, can use tools or magic, and seems to have taken up residence here. Or may even be from the dungeon itself." Dani whispered her instructions as she silently motioned the group to stop at the bottom of the last stair step with a raised palm.
Before them, at the foot of the steps, the staircase opened into a two meter high archway into a square stone room, which had a single corridor at the far end, and two wall torch holders to the left and right of it.
A nod and a silent gesture in the direction of the two torch holders from Dani was probably meant to show that she was right and everyone should take it seriously, whatever was waiting for them from now on.
Avan's sphere of influence had shrunk further, and was no longer five meters in diameter, and just as he noticed the further restriction of his perception, a premonition tingled down his spine.
Whatever he felt, it couldn't be defined precisely and was far too blurry down here, but warned despite everything that something was wrong.
Just as he was about to open his mouth, as Dani with Patris in front skeptically surveyed the two torch holders, something from the floor illuminated the room in blinding bright red light, and everyone held their arms in front of their eyes as Avan himself took in new unknown blurry presences.
"Enemies!" was all he could exclaim as he put his arm back down and stared, mesmerized and more surprised than frightened, at the human creatures that had just disappeared with a poof, along with his comrades and Linob.
Avan turned his head just enough to stare at an equally confused creature, who in turn stared at him as the teleport magic that had abducted the others seemed to somehow slip away.
Surprised and speechless, he reacted far too slowly as the vampire hastily took a step back and also dissolved into a glowing red cloud of vapor.
It was not the appearance of the creatures themselves, or the fact that they appeared to be vampires, that had left Avan so lost for words, but rather the bright glitter that had stung his eyes when he had perceived them.
"Why the bloody hell are they glittering!" he whispered, still in shock, the image of the glittering and sparkling vampires burned into his eyes.