Tibetan Buddhist teachings offer guidance about the unique opportunity that death provides to free oneself from suffering and realize the most subtle, profound and innate nature of consciousness. This not only applies to oneself, but is also true of the benefit from prayers and positive aspirations/deeds done for those who have recently died. Here are links to some resources to explore this possibility in greater depth. In particular, note that at the bottom of the page on the first link is a recording of Dza Kilung RInpoche chanting the mantra OM MANI PADME HUNG. Saying this mantra is said to bring comfort and positive result to those dying or recently dead for whom it is recited.
https://kilung.org/death-and-dying