There wasn't much of it but it was still enough to be picked up by any energy-sensitive beings in the vicinity.
Hao Xuan quickly closed his eyes and sent a portion of his consciousness into the Umbral Planes. It appeared as a see-through apparition standing in the exact same spot as his shadow, effectively using it as a glove for his soul projection.
With one eye he could witness the Umbral Planes and with the other see the mortal realms. But he could only ever interact with the physical realm like this.
Within the Umbral Planes he saw Princess Hwa's shadow with the two colors mixed just like the last time but she wasn't alone anymore. There was a soul- an ACTUAL soul of a once-living creature standing in front of her.
It must have belonged to the beast she had just buried because that small grave was now set alight by a brightly colored rainbow of colors all pouring into the artifact.