Initially, Su Zimo had no intention of joining the four immortal sects.
However, according to Astral Rain, given his current cultivation, it would take way too long for him to leave the territory of the Divine Firmament Immortal Domain and head to the Jade Firmament Immortal Domain.
The journey was long and he did not know what changes and dangers he would encounter.
If he could join one of the four immortal sects and gain the protection of the immortal sects, it would be much more convenient for him to leave the Divine Firmament Immortal Domain.
Among the four immortal sects, there were also super teleportation formations that could lead to the other immortal domains.
Over the years of roaming the upper world, Su Zimo had a deeper understanding that it would be difficult for him to establish himself in the upper world without the support of a powerful faction.