Reminder that DID isnt always "harmless", and thats okay.
Its okay if violent alters exist, its okay if you dont always have the control youd like to have over other alters decisions. Its okay to admit to yourself that whilst you need to take steps necessary to make sure ppl around you are safe, and if you cannot guarantee it - to disengage, that you had no control over what that alter did. You had no autonomy over it. You cant blame yourself over and over again for smth you had no control over.
Its best to try to work with the alter responsible for the harmful, or dangerous behaviour rather than to keep beating yourself mentally with a stick with smth you had no agency over, possibly werent even conscious for at all.
We exist in the same brain, that doesnt mean that alter is literally "you". If they were, we wouldnt exist as a DID system.
You can take responsibility for smth all you want, if youre not the one doing the harmful behaviour, you do actually need to get the alter responsible for it to feel responsible for their own actions as well. Before you get the alter on board all you can do is damage reduction and make sure you remove yourself from ppl, or distance yourself from them, or try to give the alter less "room" to act damaging.
But ultimately that alter is the part that carries the behaviour or urge, you do need to "move" the part thats responsible for the behaviour.
Ive found that very distressing, that no amount of how shit I felt over smth an alter did ultimately changed the alters behaviour or mind. And in fact made them feel antagonized by me and made them even angrier therefore.
So, yeah. Try to fix what you can fix, take responsibility for what you can take responsibility over but dont forget that the alter that did the damage needs to reach the conclusion that maybe its time to change for you to actually.. win that one, I guess.