For the majority of the Extraordinary Exponents, the Phoenix flames at the Heavenly Enlightenment Level were an absolute nightmare, even unimaginably powerful.
When he was merely at the Transmutation Level, the flames that burst forth from him could only incinerate tangible objects, but after reaching the Monarch Level, the flames could even consume many intangible things, many "invisible things" would also be completely burned by the terrifying flames.
And then, upon truly reaching "Heavenly Enlightenment," the powerful leader of the Last Blood, the "Phoenix," had flames that became even more fearsome, now able to incinerate various abstract concepts.
At this moment, he could even burn "connections" such as these into nothing.
Thus, the Phoenix's flames burst forth in the sky, as if extending to many invisible threads around, those being the numerous connections between the undead and Chris.