Can't use Cure 2

[Hysterior]

Potency doesn't even need to be lower because spell / ability damage scales off of the weapon damage stat which in synced content is lowered.

Yes but you have access to skills with potency stronger than what you should have at that level.
So to have all your skills, potency should probably still be reduced otherwise you would really break the dungeon for low-level players.
I would be more than happy to Holy in Sastasha, don't get me wrong, but it probably needs to be nerfed a bit...