@jens I am glad this is a little bit helpful. So to speed up some reading and sifting through chaff, here I dig up some stuff from my own journals:
* https://bpdfamily.com/content/karpman-drama-triangle -- also on how to escape the triangle and a lot of the context too.
* playing a rescuer role is one of the most intriguing pieces in all this. For me, it collided with my sense of "how to be a good person" which equaled (and still to some extent does equal - if left unchecked) to help others, i.e., some form of rescue - which is somehow wrong - they say... But how wrong it was, was seriously intriguing to me for a long time. Until...
* ... until I saw this: https://www.youtube.com/watch?v=jSdODaTeHXw - the most striking point was when the psychologist says that rescuer's intrinsic position is to see people as "one-down". Which horrified me (as it clashes with some other deep values hold) and opened my eyes to what is really going on.

Good luck there!