yeah i dont think u want to do that, stay here after your dead your suppose to go were your soul takes you staying behind to help guild your family members they will find there own way they dont need you to guild them and if they did they would call for your help. i think you need to leave this alone and find some thing else to do..
Question; precisely what are you hoping/expecting your descendants to get out of being able to contact or summon you?
With all the already existing ancestor spirits, angels, elementals, totems, and gods people can already contact, why will they contact you? What do you plan to offer them that this myriad of capable spirits cannot?
I ask this because according to traditions which are heavy on the worship or reverence of ancestors, like Ifa and Asatru, it is the reverence and honoring that your decedents do that will keep you in a contactable state. In other words, just be awesome. Provided that you have decedents that engage in ancestor reverence, it'll take care of itself.
As for this notion that existing as an ancestor spirit instantly disqualifies one from reincarnation, this is based on the idea that our spirits exist as a singular entity. According to Hinduism, the religion that most modern beliefs on reincarnation ultimately springs from (keeping in mind that Buddhism comes from Hinduism) this isn't the case.
Your ever-lasting soul is called your atman (not to be confused with Atman. That capitalization makes a world of difference here). Your atman is the little piece of Atman, the ever-present god that all things are made from and by, and it is generally considered the only part that truly moves from one life to another. Much lower is the unenlightened part of you which identifies as, well, YOU. It's the ego and, in Western spiritual terms, it is the astral or energetic body.
The distinction is made clear when it is said that when the Brahma Night comes (the unmaking of all things) all of us will experience oneness with Atman. However, all that is not the enlightened atman will be stripped away, meaning that only those who are enlightened and are ego-free will be consciously aware of this. For the rest of us it'll more be our spiritual proto-matter which is one with Atman. All that stuff we label as "me" is left behind.
There's also the simple fact that if our entire energetic self was reincarnated we'd perpetually be almost exactly the same person. There's overlap between them and our past lives influence our current and future lives, to be sure, but most things we consider "us" is spiritually superficial and relatively low and close to the physical, hence the reason it so closely mirrors our thoughts, emotions, and for most people, our bodies.
In Hermeticism it is generally understood that for most people this lower spiritual self, the astral or energetic body, will dissipate naturally after a few days, weeks, or months. Some may become trapped, creating ghosts and hauntings, and those who are especially strong-willed may continue to exist for much longer (as is frequently the case with magicians who are part of a magickal order or society). This doesn't prevent their atman, their true spiritual self, their "soul," from moving on; it just means the ego of this particular incarnation doesn't fall apart.
.... I feel I may have rambled, but I hope this made some measure of sense. Please let me know if I need to elucidate anything.
And as a side note, this understanding lets there be room for both reincarnation as well as judgement upon death. I personally expect that my spirit will be reincarnated yet again while the ego of this life will wait to be judged by Allah on the Judgement Day. I believe and hope that I will be allowed to aid my kin (I'm afraid I'll have no blood decedents - being transgendered sort of prevents that for most of us), provided that Allah deems me a worthy enough being to be allowed to do so.
