I found out today that my DM (in a D&D 5e game) made some tweaks to my character's backstory, specifically some of the formative parts of his 'creation'. These changes are on the border of myth and logic, which wouldn't be a problem except that she landed more on the myth side, which placed the soul in a 'death adjacent' position. My character is a twin-souls, a pair of infant twins who were gravely injured and before they died the Traveler intervened and bonded them together into a single being.
To quote my DM:
Yes but I have a system where, as [character] levels up the manifestations of his soul grow more powerful and he gets new abilities.
3rd Level: Beyond the Vale: Your eyes turn milky white and you can see through the eyes of your second soul (Ethereal Vision 10ft) 1/short or long rest.
6th Level: Ghostly Presence: You can activate this ability to make your body turn into that of a ghost (Just Appearance) and if in combat every creature that can see you must make a saving throw equal to 8 + Proficiency Bonus + Charisma Modifier. You should be dead - the Traveller is powerful but not powerful enough to remove all factors of a dead soul; the Raven Queen would never allow it.
The problem is that in my original backstory the character wasn't actually dead. Near death, but not dead. Saved from death by The Traveller. Her changes place this event within the realm of The Raven Queen, and result in the 'death adjacent' problem.
As a result I now have some problems. First, she started by telling me of two custom feats, neither of which make sense mechanically or for the character. Second, with these changes the character's whole narrative raison d'etre doesn't make sense. This is already a crazy character, but with these changes it's just really bad and I can't play that. I predict he'll be unplayable by level 6.
Playing in character is kind of the point for me, and there are some characters that are just too unrealistic, even for D&D. A crazy teenager who enjoys stabbing things, eats lunch in random sewers, and travels just wherever, is plenty crazy enough. I don't need to be adding this whole demi-ethereal, death-adjacent, half-ghost edgelord mess.
I don't know if she's going to add the feat or force me to sub the feat for one that I would have taken. Either way it's adding nonsense to a character. She seems to think this is a really cool thing, so if I let it happen and just ignore it, she's going to be more insulted in the long term. So, I have to nip this in the bud, but as cleanly and nicely as possible.
How do I tell her this without insulting her?