Secondly, it would be absolutely cool if nocturnal collective unconscious erected an actual shield with potency amount to reduce incoming damage.

Let's face it, 10% damage reduction is incredibly boring and is often under appreciated as its effects aren't readily visible. Make it so in nocturnal stance, our collective unconscious creates an umbrella of a shield, just like what Louisoix used in the calamity. Once the shield is broken, shattered pieces around the surface cracks then by choosing to continue to channel, the shield will slowly regain some potency up again.

This would make the skill so cool and again differentiates nocturnal sect from the scholar counterpart. It would feel great to feel like you are using an actual ability Louisoix have learnt, given he's Sharlayan and astrology comes from Sharlaya (my lore understanding may be off here however).