
Kei Wendt
I didn't create this headmate either, it just got revealed yesterday
At its core, tulpamancy is about convincing yourself that another part of your mind is "not you". I think this is important because it makes sense for a thoughtform in the mind to have feelings, emotions, or even a sense of self. BUT that does not mean you have to accept that part as another person.
Ultimately, it will always be a choice to accept a thoughtform as a separate person or not. There truly is no such thing as "too late", regardless how "developed" the thoughtform in question is. It is either a part of you, just something in the brain, or someone else, but you can decide which category a thoughtform falls into.
Additionally, not all thoughtforms are created equal. Some people have characters that "seem sentient" and others have tulpas that some people think are underdeveloped. What matters more is how you and/or your system views the thoughtform in question, not what other people think it is.
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With that context in hand, the more important question is what do you want? If you want to keep them, that's fine. If you don't, that's also fine. If you need more time to think about it, there's no rush. One of the mistakes we made as a system was feeling there was some magical time limit when that's not true. As for accepting the thoughtform, you may need to rethink how you all operate as a system but it doesn't need to be a crisis. We can go over different scenarios and you all can decide what's best for your system.