Casually growing stronger
His cultivation technique automatically informed him about how cultivation changed now that he was in the immortal realm. For the most part, cultivation was now divided into two steps. The first, as usual, was to absorb energy into his body and refine it, though that too had become more complex than it was before.
Basically, prior to the immortal realm, cultivators in general just generically absorbed spiritual energy. Yet that was no longer sufficient within the immortal realm. Now, he needed energies of a higher level to cultivate. If, for example, he were in an environment such as Earth, which only had low levels and concentrations of energy, not only could not cultivate at all, but replenishing his energy reserves would also take much longer than usual.