Yukka-sama
In most cases, memories from previous lives disappear soon after death, but there are also people who have past life memories.
Just the other day, there was a story about a boy who set out on a journey to find his mother from his previous life on a TV program somewhere. I only watch commercials, but...
There is quite a bit of talk about searching for parents, families, and friends from previous lives from past life memories.
Also, in Tibetan Buddhism, when high priests are reborn into this world, they may also be reborn with memories of their previous lives. That memory will be tested with possessions etc. from previous lives, and actual reincarnation will be identified.
What connects a previous life, this life, and the next will be extremely difficult, but it is a “fine consciousness and work” that is different from rough consciousness in this world.
In the case of activities in this world, that fine consciousness does not work, and the function of roughly rough consciousness mainly works, and it mainly disappears with death, but the function due to rough consciousness constantly affects fine consciousness and work, and the effects of karma due to consciousness and actions in this world will be carried over to the next life and the next.
Therefore, they are different beings that cannot be said to be the same or different.
There are probably no guardian spirits, but I think the feelings and feelings that work for you, for better or worse, may have some kind of relationship with those caused by close parents, family, or ancestors, etc.
In Buddhism, beings who have been freed from reincarnation become Arakhan, Enkaku, Dokaku, or Bodhisattva, or Nyorai, but once again, I think they are sometimes underborn for the purpose of saving those in reincarnation of their own will.
Kawaguchi Hidetoshi Gassho