It is over.
Hisame had made one critical mistake in particular: she had assumed that she was fighting some woman wielding the powers of the storm. But Procella is merely a figurehead. The storm itself is the real enemy, and it is unpredictable, vast, the combination of elemental forces into something that cannot be stopped. Of course, the storm would not have moved against this woman, had its spirit not survived this long. But Hisame had not moved aggressively to end her opponent, she had delayed and delayed and delayed as Procella grew more and more powerful. And now, as she takes almost a full minute to prepare her next attack, she will be shown that there are some powers one should never play around with.
The trees Procella had dropped on Hisame are blocked by a renewed shelter, which is surprising, given that she had so little time to muster a defense. Perhaps it is possible for her to somehow store the shield, to call the original one forth again without creating an entirely new barrier- the storm knows not, the storm cares not, all that matters is that its aim of destruction is somehow achieved. Procella notices instantly that it is not: as the first arc leaps from her carefully placed knife among the fallen trees, the charge within Hisame is not re-balanced by the striking of the bolt, and the slight leaning of the trees makes the reason obvious. Still, the plot was not entirely in vain: the woman is trapped. Now, a proper end for her can be prepared.
And so Procella begins her work.
A slight disruption quickly becomes evident, as the trapped, undying enemy begins to moan like the horrible, unnatural ghoul that she is. Even to Procella, the sound is disturbing. But sound can be evaded, for it dissipates with distance, the waves growing weaker and weaker the further away one walks. And so Procella retreats. There is no need for her to remain close, now, for the storm extends everywhere above her, and the remaining imbalance of charge in Hisame will allow her to keep track of the woman's location through the mask of trees. She moves away, letting the moan fade into the background noise, and by the time it rises to a terrifying shriek, it is but a distant irritation to Procella.
For Procella's power has been growing in two ways. First: the gathering of the storm made her stronger and stronger as it went on, and now, in a full tempest, she is twice as fast and strong as the greatest of athletes. A well-trained woman can run a mile (5280 feet) in barely over four minutes, Procella could have run it in half that time. After a few seconds of leaping and skipping through the forest, she is hundreds of feet away- and with sight masked by the fallen trees, hearing smothered by the raging storm and her own groaning and screaming, there is no way Hisame can know where the spirit had gone.
Second: the gathering of the storm brought with it concentrations of charge, in both the ground and the air, spread over huge distances. Procella had already used this once, in her grand bolt a few moments before- but that was a hasty measure, one of her little sparks scaled upwards many times. There is only so much power she can muster at short notice. But now, she has the entire storm at her disposal, and a nearly eternal minute in which to use it.
A while later, the forest explodes, leveling five hundred square feet of land. This area is not so wide as it might seem at first, but the level of destruction is fairly impressive- only Procella is far beyond its reach, having been given plenty of time to leave the area and a good reason to do so regardless of her awareness of the coming blast. Hisame can only look around her flat battlefield and see nothing, for she is looking at the wrong playground. The true arena is now wherever the stormclouds cast their shadow, and it extendeds a very long way. If Hisame survives what comes next, she will be left with a great deal of space in which to hunt for her opponent.
But by this point, her survival is doubtful.
For the first thing the possessed woman will likely notice, once she has unleashed her massive blast, is lightning- a beautiful flower in the sky, multiple chains and forks reaching out above her. They fork down from high in the clouds, coming close but never quite touching her, and it makes for quite a pretty sight. It will be the last thing Hisame ever sees.
After glimpsing it for the tiniest of moments, she will be be gone.
Procella had grown in power, and now she has been given time. Time to prepare, time to gather charges, time to carefully set things up instead of being forced to work with what she had at any given moment. Hisame had made her move, and now the storm spirit retaliates with a similarly terrifying level of power- only her move is not blunt, brutal, seeking victory through force alone. It is focused. So instead of simply building up massive concentrations of charge and hoping for the best, she restores the charge in the ground beneath Hisame (so that lightning can indeed strike twice), and then sets about building a pathway.
Lightning, being essentially a traveling current, always follows the path of least resistance. Electrons move out from the clouds above, producing a 'stepped ladder' as they go. This is the crackling flower of lightning Hisame saw above, bright because of the sheer magnitudes Procella has moving now. When these first probing tendrils from above reach towards the ground, discharges will sometimes rise up to meet them. When these meet, they produce a channel, through which charge flows through to the earth. And then, a massive, violent discharge moves upwards through this channel, the massively powerful 'return stroke,' superheating the air so quickly and brightly it only appears as a massive, jagged bridge between cloud and ground.
The movement of charge on its own is deadly enough, producing burns, electrocution, cardiac arrest. But it is already clear that this is not enough to fell Hisame. No, what Procella has done is far nastier.
With the time she was given, she has forget a bridge- not to Hisame, so that she might be struck again, but through her. So when the discharges meet, and the charge flows, Procella forces it, with all her gathered power, straight through her opponent and into the ground. And when the return stroke comes, the massive discharge headed for the clouds it comes not from above Hisame's shield, but from the earth below.
It will flow straight through her. An utterly unnatural strike, traversing a body rather than the air, but Procella had been given plenty of time in which to ready this difficult strike.
And with this much charge moving so fast, in a channel about the width of a thumb, the danger is not simply in the current, but in the heat. The core of a return stroke can reach temperatures of over fifty thousand degrees kelvin, several times what one might find on the surface of the sun. Though this is concentrated in a small area, heat has a tendency to spread, and this ought to be more than enough to simply vaporize the small body. Needless to say, this happens too fast for one to even perceive its movement, let alone attempt avoidance.
But perhaps Hisame is more resilient than some, and can survive the initial bolt. Well, it is not over.
If an imbalance of charge remains after a strike (and Procella would make sure of that), the channel through which the lightning passed remains conductive. Through this passes a 'dart leader,' a flow of negative charge moving down to the ground again. Once it has arrived? Another return stroke. Which, in turn, paves the way for another dart leader. In some cases, this can result in over twenty strikes in a row, and Procella, with all her fury, will make certain that many occur.
Suffice to say, Hisame's body would be utterly destroyed.