Krune and Feifei didn't wait to return to the Luvile Universe. Krune simply used his Purple Tribulation Lightning to cover themselves from Spiritual Senses and headed straight back to the Luvile Universe. After all, if the real one appeared, she would pass through the same process as Krune. Everyone at the Divinity Realm would notice the birth of a new Heavenly Core, just like what happened to Krune.
After they headed back, Feifei took the two fragments out to try absorbing them. The first one turned out to be a Yin Heavenly Fragment, which she already had. Fortunately, she lucked out in the second one as it was the Time Heavenly Fragment she sorely needed. Feifei's cracked core turned into a liquid together with the Time Heavenly Fragment before fusing together not long after.