Manga/Anime I read/have read/tried to read:
What chakra type are you?
On the other hand, there are jutsu that allows you to take over someone's body (like Ino's), so it's possible that, if the target's power isn't solely based on spirit, it would be possible to use that person's bloodline limit.
it doesnt really have to be a brother tho, from what ive read its a matter of blood ties, the closer the better compatibility, but then again, an uchiha is an uchiha that should be close enough.
But imagine if 3 immediate fam members had mangekyo sharingans and you swapped two times.....i wonder if u would have some sort of super ems or something resembling the eyes of the uchiha ancestor.
Hmmmmmm, but what if someone took the normal sharingan of his brother and gave it someone else, who later awakened MS and then retrieved it from him, then would he still gain EMS ?
It just seems that Hashirama's power is so much easily transfered to people that aren't even related to him, when a swap of MS doesn't even work within one clan, but only for brothers (at least for all we know).