Being one of the few Four-Star Artifact Refiners in the Great Turdo Dynasty, Valiant Charlesworth had deep knowledge in 'artefact refining'.
This is precisely why he understood what it meant for a Third-Rank Artefact to amplify 'seven-tenths' of the power.
As the Vice-President of the Artifact Refiners Association of the Great Turdo Dynasty, Charlesworth's understanding of artifact refiners extended well beyond the Great Turdo Dynasty and neighboring dynasties.
After all, there was also an Artifact Refiners Association in the distant 'outside territory'.
Moreover, every few decades, the Artifact Refiners Association from the 'outside territory' would send special envoys to the headquarters of the Great Turdo Dynasty's Artifact Refiners Association to provide guidance in artefact refining.
These envoys were, at the very least, 'Three-Star Artifact Refiners'.