Hmmm... not sure if my experience can be of much help, other than to show how DIFFERENT each DID system can be....
Two of my insiders just "fused" about 2 months ago... (1st time it's ever happened

)
I had no idea it would happen, and neither did they... "The System" just
did it, i guess.
*note: all of my alters are totally separate on the inside, they do not see or know each other, they have lived their whole lives in isolation (most of them 41 years)
Jabbekpheka fused with Domella, and became a whole NEW ALTER named Nanette.
Nanette has NO memory of (or memories from) or even knowledge of Domella or Jabbek's existence
When she came into existence, she had no idea who she was, where she was, why she was here, etc.
It happened because I completely HEALED from the trauma that created Jabbbek (a surgery 3yrs ago)
I guess she was fused with Domella because they were both sexual-protector alters...(?)
I definitely experienced a period of grieving for the loss of D & J... but it was brief.
I adore Nanette, she's a sassy li'l hottie and has blue hair ~ pretty out of the ordinary for us!
~ But ~ I think I can relate to what other are saying about having a feeling of more 'wholeness' or whatever... there is a certain sexual issue I have struggled with my whole life...
Ok I will be forthcoming and say that I have always been able to fantasize about sex with my lover, but unable to
initiate it ~ and that issue has totally gone away. It does feel as if something has "clicked" into place, more "connected" somehow... more "whole" I suppose. More natural.
This seems really different from what I've read about others; there are some who have several alters fused into one, but any one of their alters can "un-fuse" at will and do something individually before fusing back together again... my system is not made that way at all. Once a change happens, it is permanent and irreversible in my system. We are all SO UNIQUE!