Why are some base game spells missing from nightreign?

There’s a handful of sorceries that are completely absent from nightreign’s spell list like:

- Lucidity
- Starlight
- Unseen Form+Blade
- Fia’s Mist
- Lord’s Aid
- Cure Poison
- Assassin’s Approach
- Order Healing
- Vyke’s Dragonbolt
- Flame, cleanse me
- Bestial Constitution
- Inescapable Frenzy (would be useless mostly, but what if it did damage to invaders??)

Ofc most of them aren’t helpful but its weird that we can have useless incantations like Shadow Bait, Darkness, and Law of Casuality but we can’t get Fia’s mist or starlight.

I did notice that a lot of anti-ailment spells and incants are missing which is probably on purpose, but then why keep Law of Regression?