After his fight with Huo Yi in the Despair Fire Kingdom, Ka Suo was stripped of his powers. To me, the way everyone was talking about things, there was no easy way to restore his powers. People discussed extreme things like finding Spirit Snow Mountain or killing another immortal as a means of restoring spiritual power, and Li Luo went to find She Yin in order to ask about restoring Ka Suo's power.
It is true that Li Luo came back with the information on how to summon the Fallen Oracle. But my understanding was that the Oracle merely devoured the sword spirits inside Ka Suo, returning him to the way he was before he took the sword spirits in: i.e. healthy, but essentially mortal.
However, it seems that Ka Suo's spiritual power started returning, and unless I missed something, it wasn't treated as much of a surprise. If anything, it was connected to the Fallen Oracle eliminating the sword spirits, but that doesn't seem to make sense.
Why did this happen?