The trainer smirks as she points at a 3d display of a generic body with the three runes connected at the heart. “The war stomp is a simple enough skill for all it uses internal runes and has so many years behind it. See, to activate it you take the output of your core rune.” She makes the display highlight the displayed core runes output and draw a small arrow coming off of it. “And you point it at your leg.”

The trainer snaps her fingers and the display animates. A stream of power enters the trio of runes and when that power comes out it follows the same pattern Jason had seen enough already. One beam becomes many through the creation of more runes. The difference is that instead of petering off this mass of power seems more guided. The general direction the beams all fire off at tends more towards the chosen leg.

However when the first beam reaches the leg everything changes. It stops right at the entrance to the limb and forms a rune twice as big as any other. The other still active runes all become directed towards this one big rune and every new beam is now directed towards it. One multiple beams of power has hit the big rune a beam of power as wide as the rune fires off towards the knee. Once there another rune which just barely fits there takes shape like a giant sphere.

Then a series of beams fires off from the edge of that rune towards the ankle where they meat. Jason barely has time to see a tiny rune form there before a spike of power extends out of the foot from the heel. The trainer pauses the display, “that’s it. Just point it at the leg and your golden. Maybe literally depending on how your powers react with it. I know one guy using the publicly available version has their skin turn into ironwood when he uses it with his nature power. Someone with a more gold aligned metal power could turn into gold I bet.”

Jason nods, “yeah that would be interesting. Though I have to ask, what happens if you point the core rune towards somewhere else?”

As his question the trainer smiles and claps. “A good question! It is possible to use this skill with other limbs, eventually. Now it has to be a limb because as you might have noticed, that focuses the power. Though most sentients have a few limbs or at least some limb stand in so that isn’t too limiting of a factor. However you won’t be able to use it like that without a lot of practice and training.”

She taps the display and it replays the previous example except point at the arm. When the runes reach the arm though the rune formed is too big and the skill fizzles. “With no control over the skill that happens. The reason I use it with the leg is because on most humanoids that is the thickest limb. Now this isn’t a problem if you're using the skill with external runes but then you get limited by the skill forming them at your feet.”

“Oh, and don’t try to use your head until you master the skill. While on the inside your power generally won’t hurt you, this is a lot of juice being pumped through. Scrambled thoughts are only acceptable when being figurative, not literal. Now step over there and try the skill on that dummy.” And she points towards one of the training dummies that is already laid down on the floor.

Jason bows towards her and moves to stand over it. After a moment to steady himself Jason forms the runes pointed in the right direction and inserts his Energy. The new runes and beams of power form as the display had shown. When the multiple beams collect at his ankle though nothing happens.

They stand there for a moment until the teacher facepalms. “Oh right, once the power gathers at the end of your leg it is ready and you just have to stomp on something. If you wait too long the runes will start to fade and the power will decrease. But hey, that’s a lot better than when it just exploded!”

Jason rolls his eyes at that. “Yes, fading away does tend to be better than explosions when dealing with internal energies.” Then he stomps the dummy. At this point what happens differs from the example. Instead of some spike his Energy flows into the dummy and seems to shatter into thousands of threads.

The dummy is completely unable to resist of course and is soon reduced to scrap by Jason’s Energy. Jason turns to the teacher to ask something only to find her right next to him with a piece of the dummy in her hand. He keeps quiet and just observe for the moment and is shocked by what he sees. The piece of dummy she holds is still being broken down until the chunk is reduced to dust.

She nods, “Good thing you only got around to learning the skill just now. Whatever you’ve done with your cultivation has affected your Energy to the point that even your results with war stomp have been altered. If you had managed the skill before whatever you did the System would have set the outcome of the skill and I doubt it would be as useful as this.”

Turning to Jason she dumps the dust out of her hand only for it to disappear before it can hit the floor. He glances back at where the dummy was only to find there is nothing left of it, not even a speck. She sighs, “don’t expect this sort of outcome. Using it on living beings or really anything with its own energy field which would include the world itself will stop the attack after a while. These dummies are just hunks of powerless wood to allow a better understanding of how a skill works.”

“This result takes Energies endless cycle and combines it with whatever you did to turn your own energy into threads to create endless destruction. Endless of course only in theory as I have already said. While if there is nothing to stop it the attack will keep damaging things but any other power will oppose it with both wearing themselves down. Against weaker foes even if it doesn’t kill them they will run out of power. Against stronger foes it might not even cause damage though will force them to move their own power to fight it so could provide a distraction.”