A wall of text with no punctuation is not something I am going to spend ages deciphering, instead I am going to assume that your question is: "I say, chaps! I seem to be having an awful bother with these confounded Nightsisters! Please help!"
So assuming I'm right, what you are looking for is attacks that can hit multiple targets and, if you can, buff cancellation.
Whenever possible, hit Old Daka; if the Zombie's taunt is on then either cancel it or kill the zombie to get rid of its taunt. Then go back to hitting Old Daka. Once she is dead, the Zombie will revive her. This will happen twice. Once the Zombie has used up its two revives, then you can really go to town.
Kill Daka one more time, this stops her reviving anyone else.
Then unleash and take out anyone not stealthed.
If you're up against the usual Nightsisters team, you will be eventually be confronted with Zombie and Miss Permanent Stealth. This is where your attacks against multiple targets come in. Fire them all off and kill Miss Permanent Stealth.
Then destroy the Zombie one last time.
One of the easiest teams to do all this with is Phoenix.
You have Sabine's grenades for hitting Miss Permanent Stealth, Ezra and Chopper for cancelling Buffs, Kanan Wall for soaking damage, and Hera for reviving your own characters.
Failing that, Sith are good if you have them.
Darth Vader in lead will keep recasting Damage Over Time on anyone who ever gets it. This is great against Miss Permanent Stealth.
The Emperor and Nihilus and Sion all hit multiple targets and the latter two cancel buffs as well.