The Following are 2 scenarios I'd like to keep out of the discussion, as I feel that they're too circumstantial. , if you feel very strongly that one of these 2 scenarios is what would in fact actually happen, feel free to post about it, so long as you address the issue of likelihood that comes with it.
- Neither Fighter knows anything about the other fighter
- General knowledge of each from both universes is available to each fighter. I.E. Byakuya knows of and about sharingan eyes, but he's not aware Itachi has them.
- Byakuya's being a spirit (which, in the bleach universe, may be unaffected by the physical world.) will not be factored in. In other words, No saying "Itachi can't even touch him!"
- Itachi's eye sight is fine