Yu Tian's core was vibrating intensely.
It was beginning to transform into a Golden Core.
But if he let it transform naturally, it would just be a normal Golden Core.
He retrieved the core from Su Qing and began absorbing it. Su Qing's core had absorbed the cores of many other Core Formation experts and was quite solid. If he absorbed it fully, he should be able to form the Absolute Core that Su Qing had been seeking to create.
He also had the other cores he'd gotten from the Dark Moon Hall attackers. He could use these to finalize the core, or even to advance his realm after breaking through.
As he did all this, the lightning was still continuously striking at them. At the moment, it was still manageable. He was using his qi to protect himself. Though it didn't seem to be working all that well. Either way, he could still handle the incoming damage. Though not for long - the lightning seemed to be getting stronger with each strike.