Absorbing lightning

Ethniu raised the spear and it transformed again into lightning in her hand. She swept a baleful gaze around the battlefield, choosing which target was the most dangerous.
She focused on me for a second. Then, longer, on the Archive. But then her eyes settled on my grandfather. On the Blackstaff in his left hand. Something about it seemed to stoke the furnace of her rage.
“Little boys should not play with adult tools,” the Titan snarled.
The old man’s answer was to raise the Blackstaff, shadow engulfing his head and shoulders, and to make a sweeping, beckoning gesture.
The front rank of the line of Fomor troopers died in their tracks, clattering to the ground.
Ethniu howled and unleashed the lightning against my grandfather.
The stocky old man vanished farther into shadow, raising the Blackstaff, the weapon’s darkness devouring the lightning, drinking and drinking endlessly—until I could see actinic fire gathering in the cracks of the old man’s skin. It did weird things to the shadow he cast, twisting and distorting it until it looked like a hideously twisted old woman, complete with the classic witch nose and chin, looking somehow darkly amused.
The instant Ethniu brought her fire down upon the old man, the Archive tilted her head slightly and lifted a single finger. In that instant, the whirling screen of big heavy things went flying toward the Titan in rapid succession like stones loosed from a giant’s sling. They hammered Ethniu, striking clouds of sparks from the Titanic bronze armor over her skin, battering her back off the top of her mound of bodies, and sending the bolt of energy trailing up into the sky.
My grandfather staggered and fell to a knee, silver light seething from beneath his skin, showing the dark shadows of liver spots, the lines of the bones in his right hand. Then he lifted that hand, holding what looked like a blazing gemstone the size of a softball, and with a word and a gesture sent damned near every erg of energy he’d just received sailing back at the Titan’s position, wreaking havoc among her troops.

Battle Ground Chapter 32, Page 308-309