New Spire effect: Reduces MP costs for target by 10%.
This would compliment it's counterpart in Ewer, while Ewer would recover lost MP, Spire would preserve MP, and with TP merging into MP this will benefit anyone.

Sects effect cards: Current effects are present in Diurnal Sect*, new effects for Nocturnal Sect target enemies instead of party.
Balance: Enemy deals 8% less damage for 15s.
Bole: Enemy takes 8% more damage for 15s. (does not stack with Trick attack)
Arrow: Enemy’s attack speed is reduced by 10% for 15s. (but certain special moves and phase changes are unaffected)
Spear: Enemy cannot deal critical hits for 15s.
Ewer: Inflicts a 50 potency DoT for 15s.
Spire: Enemy takes 10% of the damage they inflict on any party members for 15s.

The point of this is to allow dual-AST compositions to use their cards without worrying about overwriting the other’s effects.
The duration is nerfed to 15s for Nocturnal effects as they could be more OP than party buffs, with Bole/Balance nerfed in potency to 8% as well.
*Diurnal Balance and Bole also nerfed to 8% effect.

I think this would also see Nocturnal Sect favoured more over Diurnal in some ways, due to an Enhanced Bole being more effective than Trick attack. (12% more damage over 15s) Would be a neat way of improving the currently inferior Nocturnal Sect.