Both Xiong Jingnan and Michelle Nicolini have a rival in-common : Angela Lee.
To this day, Michelle holds a grudge against Angela because :
WHen Michelle 1st joined One Championship, in their 1st training session together, Michelle says Angela didn't hold back and tutor Michelle in striking, instead Michelle complained Angela was mercilessly beating Michelle up using Muay Thai, to which Angela retorts "grow up, you're in MMA now".
Plus, both Angela and Michelle believe themself to be better in BJJ than the other fighter. So a natural rivalry there, fuels their emnity.