I do understand why they felt they had to fight it out over this, and why Anis had to lose (because if she won, her life would be hell, even if it was "her decision" to go that route).
The thing that bothers me is Euphie effectively giving up her humanity and her eventual memory of Anis just in the process of saving Anis from herself; which is just going to hurt Anis in a different way. Sure, she's no longer going to be a Baby Factory to some old man noble, and that's fantastic. But...the one person she loves more than anything except magic, will become an inhuman monster (well, not a bad monster, but certainly not the Euphie of Old) for her sake.
I think it's great from a "tragedy" perspective, except that I kind of suspect that the story isn't going to have a sad ending with Immortal Euphie watching Anis die of old age only to eventually forget her.
Just sucks to be Anis in this story, at the end of the day, as I'd elucidated before. I guess this way she gets to live a relatively free life and can work on her Magitec stuff, and she gets to ostensibly spend her life with Euphie, which is a definite upgrade over the alternative.
Unless awakening the Dragon Mark pulls some Author Fiat and makes her Surprise Immortal or something, which also would feel like a copout if I'm honest. I think I'd almost rather a bittersweet/tragic end than a macguffin that removes the stakes of what they just put themselves through, like it didn't actually matter at all.
I suppose we'll see, though. I believe the anime ended shortly after this point, and I've not read the novels/know how far they cover. so I can only guess at where we go from here.
But, thank you for the chapter.