Even if we're broke, the sect wouldn't press Lu Chang'sheng for repayment just because of this second-grade early-stage magical artifact.
In fact, they'd love for Lu Chang'sheng to not pay it back—it'd be another favor they could call on.
Once you reach Foundation Establishment Realm, the Immortal Contract you signed earlier doesn't carry much weight anymore. The main constraint of this low-grade contract is the jump from Qi Cultivation to Foundation Establishment. Once everyone's made that leap, there's not much holding you back.
At most, it'd be for the next Great Realm advancement.
But that means the person has reached late Foundation Establishment, and cultivators at that stage are already a threat to a small Domain Immortal Sect like Good Beast Sect. Normally, they'd bend over backwards to appease you, terrified you'll leave. They wouldn't dare bring up the topic of a minor magical artifact.
In short, Lu Chang'sheng has already become Good Beast Sect's prized treasure.
