Krune ate a Rank 4 God Stone. Though, he wasn't actually eating it. Instead, he placed it in his mouth while using his cultivation technique to absorb the Godly Energy from it. As he was fighting using both his hands and since everything beyond his figure was a clash of godly abilities, he wouldn't be able to recover his Godly Energy.
With that in mind, he placed it in his mouth to siphon Godly Energy from it constantly and replenish his expended reserves.
After all, even though he behaved as if everything was according to his plans, in actuality, he was slowly losing his cool. Kirena was stronger than he had expected. He could say with assurance that she was by far the strongest opponent he had faced in the God Realm.
Even though she fell victim to his attacks time and again, a battle between cultivators with Spiritual Incarnations wasn't like that. It depended on which side exhausted their Godly Energy first.
