Krune wasn't the only one who entered the Golden Stars level. Both Feifei and Heavin had achieved the same thing. Heavin was now considered a One Golden Stars Puppeteer, while Feifei was even further as a Four Golden Stars Formations Master.
Feifei's case is totally expected. Her laws are very well developed, only losing to Krune. She was also using her Destiny Major Divine Soul in the process, so her rate of improvement was to be this fast, at least.
She could have gone even further, but because of the baby, Feifei has to stop to absorb Spiritual Energy several times.
As for Heavin, he partnered up with Krune. Heavin was making the designs of the puppets while Krune created the parts with his Purple Flames. Of course, Puppets used other materials that aren't metals, so Heavin had to create those by himself.
Still, with the addition of the metallic parts made with Purple Flame, Heavin's puppets increased in level by quite a lot.