Sansara Sage Lin Lehan took his time to get his thoughts together before verbalizing them in Nira's audience.
"Those of us who have reached S-Plus-Rank would eventually die because there's no way forward for us after reaching the Saint Rank. The requirements to move forward are too harsh and not something any particular Path can get around.
There's only one way to move forward. And that is to live as many lives as possible through the clones, extract experiences from them and finally combine them together before our 'deadline' approaches.
Of course, we can also take a faith-centric route, become demi-gods and try to become gods to achieve true immortality. However, I never liked that route simply because it is too dependent on others' faith.