Random thought. I think Sesshomaru's Tenseiga would be able to do horrific damage to curses from JJK. It's sorta like that universe's form of positive curse energy.
Plus the fact that Sesshomaru can see the creatures from the underworld, but was also able to differentiate the enemy's true form based off of smell might mean demons (at least dog demons) in Inuyasha can perceive the soul a bit.
Which means it is likely Sesshomaru could actually do damage to Mahito if they to get into a fight! (Definitely think Tenseiga would protect Sesshomaru from Idle Transfiguation for at least a bit).
Also I like to think that if Frieren had to meet Sesshomaru and Inuyasha, because they do not have mana, she would not see them as demons at first (at least Sesshomaru who looks pretty human, Inuyasha does have the dog ears).
Maybe she would be able to tell just from aura or vibe they were demons, but them being around humans would probably cause her to not instantly blow them up. Inuyasha being half demon but also surrounded by 3 humans, and Sesshomaru has Rin to vouch for him would absolutely make her not destroy them immediately (I've only seen most of the original series, so whatever is going on with Sesshomaru and Rin in the second series is something I ignore).
ANYWAY! All this to say, I had a fun dream where the characters from Inuyasha, Frieren, JJK, and actually Steven Universe were placed in the same area! It was a neat little dream and Sesshomaru revived Stark then went to go hunt down curses with Yuji because Tenseiga told him to do so.
