I mean - that passage KoD in looked pretty cut and dried to me.

By the time he reached young Bornhold, he had achieved what Gareth and Henre called the oneness. Floating in emptiness, he drew his sword from the scabbard Bornhold proffered, and the slightly curved blade became a part of him.

"What did he say?" Dain asked. "For a moment there, your face was murderous."

Byar gripped Dain's arm. "Don't distract him." He muttered.

Galad was not distracted. Every creak of saddle leather was clear and distinct, every ringing stamp of hoof on paving stone. He could hear flies buzzing ten feet away as though they were at his ear. He almost thought he could see the movement of their wings. He was one with the flies, the courtyard, and with the two men.

From the first time I read this, I read it as the sensory enhancement you get while holding the Power. Considering Galad's age, he's either coming into it late or he's weathered it and is now a wilder. He's certainly very, very genetically predisposed to it.

Either way, it doesn't seem to serve much purpose in the series, though it would be interesting to see his somewhat sociopathic worldview shatter if someone told him about it.