During his cultivation these past eight days, Cale had examined a page from the Book of Endless Refinement and discovered something interesting - Elemental Cauldrons.
The concept was elegant and new in its simplicity. Elemental cauldrons could only be refined within elemental fields — fire fields, lightning fields, wind fields, and so on. Such fields were rare, though many major sects maintained them. If one successfully obtained elemental affinity from all five elements' fields, the pills and elixirs they refined would become the absolute best of their tier.
A normal tier 5 pill versus a tier 5 pill refined through five elemental cauldrons was a massive difference in quality and potency.
Since Cale himself was the cauldron in this scenario, he simply needed to personally attune himself to these five elemental fields by visiting each one of them. No need to purchase a high-tier cauldron and risk drawing constant attention from those seeking to steal it.
