After doing some research online to find out who is the best follower in Skyrim (I originally thought they were companions, but there’s a faction called The Companions and I didn’t mean them), it seems there is a choice of three who are the top candidates for being the best follower.
The one problem is that two of them are Mages unless you count the one from the Companions, but anyway, I chose Mjoll the Lioness as apparently, she’s an essential character that can’t die by any means. Not even by you if you accidentally swing your weapon and hit her or if she’s low on health and a random arrow suddenly pops into her and takes her out.
Her quest was surprisingly easy, all you have to do is retrieve her sword of which she lost due to almost dying in the place, but when going to the place, going through and reaching the end, it makes you wonder if she’s really that tough and why she’s essential and can’t die.
Anyway, she’s following me now and I guess we’ll see just how immortal she is…