like no bullshit no limit fallacy arguments (Itachi's Yata Mirror is an example tbh),
You know Sharingan is a massive part of Itachi arsenal. Let alone that, we don't even know how Amaterasu would work on other verse character. Unless they have some absolute immunity to fire.
spiritual energy is often equalized to spare all the headache when it comes to reijatsu, chakra, haki and ki discussions
That's a problem in itself,
Even if they are equalised there properties are entirely different.
Chakra can disrupts the flow and break genjutsu, Idk if Haki can.
Chakra can used as Projection type material to avoid Amaterasu like Naruto did and even that was burned off.
Kisame has Samehada which sucks chakra of opponent and wielder alike, can it suck opponent haki too?
As I said too many buts and ifs to carry.
And if are taking only physical prowess in account in multiverse battle.
Itachi and Kisame are literally trained ninja with high Sensory skills or reaction speed without chakra. 1v1 CQC ninja's gets a easy win.