Here is my idea for Mori adjustments.
Cypress mori can stay the way it is. It's already has a very specific condition. And not effects game play at all.
Ivory mori should be a pink or purple rarity. It can stay the same contextually. Eliminating one survivor early in game is a legit strategy and can be really powerful.
Ebony mori, however. It can still grant 4 kills, but requirement should changed to applicable to survivors on death hook. This way mori won't effect the outcome and not changed the game play.
For example yesterday I used Ebony mori on a group of 4 SWF, and changed the game completely. They were good so I could have get 1 maybe 2 kills at the end of the trial, but when I am not bound to a second hook, game ended pretty quickly. Even I felt bad for their experience, so I can imagine theirs.
In this way killing by your own hands will be there. But they won't be total game changer.