"Blaze's Qualitative Power Leap" 

When the little Phoenix hugged the holy Phoenix, their position was quite close and Blaze was even close to touching the Holy Phoenix's chest where her vital organ was. 

Now, just imagine if the Yin Flame spread from there. 

Yes. Blaze targeted the heart of the holy Phoenix and wanted to burn the heart with her Yin Flame! 

Although her Yin Flame didn't have as much heat as other types of Yang flame or fiery flame types, the Yin Flame was still a flame in essence and it was not a big problem to burn what should be burned. 

Blaze knew that if she relied on her own strength and didn't deceive the holy Phoenix, her chance to win would be so low that it was non-existent. 

However, after Blaze broke free from the illusion, she could feel a qualitative leap in her own body and she was really only a step away from becoming a sacred beast.