"Recently, I've reached the Integration Realm; even if I am faced with a cultivator at the peak of Integration, I can consume one year of my own Yang lifespan to reduce theirs by ten years... Even facing a Mahayana Individual Immortal, with my eighty thousand years of lifespan, I could reduce theirs by eight thousand..."
This fact actually carries considerable deterrence for Mahayana Monks.
After all, from Fang Xi's perspective, if lifespan is consumed so dramatically, it's quite possible the Heaven Tribulations for those at Mahayana level could arrive sooner.
After all, the catastrophes faced by Mahayana Monks are not governed by the progress of their realm, but by the passage of time...
"And this is merely the beginner's level of this supreme divine skill!"
The Supreme Northern Dipper Life-controlling Divine Skills have three stages: beginner, small accomplishments, and great accomplishments.