Consider the following, immediately before the storm:
In [u]Lord Foul's Bane[/u] was wrote:When they reached the open valley, they found dark clouds piling over them out of the north. Tensely, Atiaran looked at the sky, smelled the sir; she seemed distraught by the coming rain. Her reaction made the boiling thunderheads appear ominous to Covenant, and when she turned sharply down the valley to resume her northward path, he hurried after her, calling out, "What's the matter?"
"Ill upon evil," she replied. "Do you not smell it? The Land is unquiet."
"What's wrong?"
"I do not know," she murmured so quietly that he could barely hear her. "There is a shadow in the air. And this rain-! Ah, the Land!"
"What's wrong with rain? Don't you get rain in the spring?"
Donaldson could have mentioned Covenant sensing the illness with his heath-sense, , or even grant him a vague impression, but he does not. Atiaran's reaction, on the other hand, indicates that the feeling of ill is very strong -
ill upon evil - and that she expects anyone would sense it -
Do you not smell it?. But Covenant does not, despite Atiaran bringing it to his attention.
Immediately after the lightning blast,
The blast threw him up the hill to his right. For uncounted moments, he lay dazed, conscious only of the power of the detonation and the flaming pain in his hand. His wedding ring seemed to be on fire. But when he recovered enough to look, he could see no mark on his fingers, and the pain faded away while he was still hunting for its source.
He shook his head, thrust himself into a sitting position. There were no signs of the blast anywhere around him. He was numbly aware that something had changed, but in his confusion he could not identify what it was.
He was numbly aware that something has changed. Donaldson tells us pretty directly that something happened here which changed Covenant. This is reiterated a few paragraphs later.
Toward evening, he had regained enough of himself to be glad when Atiaran found a Waymeet, and he checked over his body carefully for any hidden injuries while his clothes dried by the graveling. But he still felt dazed by what had happened. He could not shake the odd impression that whatever force had changed the fury of the storm had altered him also.
Covenant's 'sense of mental dullness' is gone the next day. When it wears off, a couple of paragraphs later:
The next day broke clear, crisp, and glorious, and he and Atiaran left the Waymeet early in the new spring dawn. After the strain of the previous day, Covenant felt keenly alert to the joyous freshness of the air and the sparkle of dampness on the grass, the sheen on the heather and the bursting flavor of the treasure-berries. The Land around him struck him as if he had never noticed its beauty before. Its vitality seemed curiously tangible to his senses. He felt that he could see spring fructifying within the trees, the grass, the flowers, hear the excitement of the calling birds, smell the newness of the buds and the cleanliness of the air.
Clearly, Coventant now has the health sense. And it didn't come on him gradually, it
struck him. Not in only a small portion, but
keenly, with all his senses.
Later on, we again encounter another feeling of illness. Exactly the same thing that happened on the previous day, except this time Covenant's response is notably - contrastingly - different.
Then abruptly Atiaran stopped and looked about her. A grimace of distaste and concern tightened her features as she sampled the breeze. She moved her head around intently, as if she were trying to locate the source of a threat. Covenant followed her example, and as he did so, a thrill of recognition ran through him. He could tell that there was indeed something wrong in the air, something false. It did not arise in his immediate vicinity-the scents of the trees and turf and flowers, the lush afterward of rain, were all as they should be-but it lurked behind those smells like something uneasy, out of place, unnatural in the distance. He understood instinctively that it was the odor of ill - the odor of premeditated disease.
One day, Covenant cannot sense ill, even when it is pointed out to him. The next day, he can, and he even understands with
a thrill of recognition that this is a new experience, not felt before. And then Covenant makes an
intuitive leap.
A moment later, the breeze shifted; the odor vanished. But that ill smell had heightened his perceptions; the contrast vivified his sense of the vitality of his surroundings. With an intuitive leap, he grasped the change which had taken place within him or for him. In some way that completely amazed him, his senses had gained a new dimension. He looked at the grass, smelled its freshness-and saw its verdancy, its springing life, its fitness. Jerking his eyes to a nearby aliantha, he received an impression of potency, health, that dumbfounded him. His thoughts reeled, groped, then suddenly clarified around the image of health. He was seeing health, smelling natural fitness and vitality, hearing the true exuberance of spring. Health was as vivid around him as if the spirit of the Land's life had become palpable, incarnate. It was as if he had stepped without warning into an altogether different universe. Even Atiaran -- she was gazing at his entrancement with puzzled surprise -- was manifestly healthy, though her life was complicated by uneasiness, fatigue, pain, resolution.
There are no earlier hints at having health-sense; just the recognition of the beauty of the Land which is evident to even mundane senses. Then, in the span of about one day, Covenant has gone from no perceptible health-sense to
heightened,
vivid,
manifestly present health-sense. Covenant is changed, the change is palpably evident, and he knows he's changed, and he knows it's due to the storm.
Do we have any reason to doubt Covenant's impressions?
The only question left is, what was it that changed Covenant? Was it the evil storm, created by Drool? Was it the wild magic? Or was it merely coincidence that the change occurred at this time? Could Foul have construed this to occur by guiding Drool's hand?
I choose to believe that the wild magic, which ever operates unconsciously on Covenant's behalf, was triggered when it became obvious that Covenant lacked any health-sense, and that he was endangered thereby, and it 'healed him' in a way similar to the way it healed him on Kevin's Watch in the Second Chronicles.