
A long kiss goodnight
the problem with possession in general is you allow things to controll you and open yourself to other unconscious possessions that you probably will never find, but are like parassitic, also you become less aware and give the commands of your life to something that is not you (could be even an angel.. is not right) so will start as when many people use magic, and they are not really living without it, and the object start to influence the subject in the way that your essence will be a little part in your body that think to have controll.
This is not the tulpamancy understanding of possession. In the tulpa community, possession means allowing your tulpa to control the body while the host still can take back control, intentionally or accidentally.
You may be referring to switching. Switching is when a tulpa and host trade places where the tulpa basically becomes the host and vice versa. In this case if a tulpamancer believed they could switch with anything and those things could potentially hurt them, then I can see how that mindset would hurt them a lot.
While possession and switching are generally safe as normally taught in the tulpa community, I'm curious if you are reporting issues you have seen in another magical community. If that's a common result, I'm wondering why it's taught like that. i had a friend that used to let the tulpas controll him for things that he wasnt able (for what he said), also used on drive, have sex, energetic treatments, etc.. (was powerfull)
but one of them was a bit.. out of controll.. so made energetic things that where bad.. and other things..
he was totally under the influence of his creation, was like an autist and his creation was the gang who was telling him what to do.
and we had to focus him on one of them.. because was taking controll and modify is perception.
i mean, i had two useful tulpas, and some of them where following me without direct problems, and i had benefits, also when i was working with energy, i tested new ways to create and use energy etc.. but about possessions and let them controll.. i think you open doors without thinking about close them.. and without the full consciousness. (edited)