well, everybody in narutoverse has chakra, even the animals. this is because chakra was spread across the world by the sage. hogoromo exist as floating chakra, thus all he is is chakra. that is only the case bacuse in narutoverse they presumably only have an afterlife because of chakra. the same cannot be said for bleachverse. in bleach they only work with spiritual energy, or better known as reiatsu. in narutoverse, spiritual energy would only make up half of what chakra is. in bleach, spirits, thus shinigami, are beings made entirely of spiritual energy. thus shinigami do not posses physical energy, because they don't have physical bodies. maybe quincy could because they have actual bodies. or maybe even someone using a gigai. but you are right in that it wouldn't matter anyhow. aizen would outclass itachi in everything anyways.
