@Retex the higher dimensional thing is a misinterpretation that kubo has actually addressed in an Q&A, when Aizen “transcended” he simply surpassed the boundaries of the soul, he didn’t actually reach a higher dimensionality, and dangai ichigo was able to be injured by said aizen, so either kubo contradicted himself/retconned it making aizen and ichigo no longer higher dimensional, or occum’s razor, they were never higher dimensional to begin with.
Both naruto and ichigo are uni cause they both use the same wording in practically identical contexts, when talking about their worlds/diminsions “世界(sekai)” which means world, universe, society. Sekai is used for Kaguya’s diminsions and for the 3 worlds of bleach.
tho if we were to bring in the boruto movie then naruto would actually have a better argument for uni than ichigo has. In the official canon novel for the movie they use “宇宙(Uchū)” which means space, universe, cosmos. Uchū is used when momoshikis diminsion is described.