Q: Can the ego be thoroughly rejected?
If it is not ever indulged in thought, speech or action, it will not return. That is the full rejection.
Q: I find that even the descents cannot change or purify the ego and desire.
It is not descents that can do [it]. It is either psychic rejection or the settling of the higher consciousness in the lower nature or both together that can do it.
– Sri Aurobindo