So what makes Noct as harder?
I havnt played it much so I can't say.
It can't be the regular shield since, beside the crit factor, they function the same.
Celestial opposition brings more shield as an ogcd. Basically a deploy.

What I would see lacking is a proper sacred soil equivalent. Sure we have CI but it's long cooldown and potency nerf makes it strictly inferior in every regard. (not even talking about the '' not move. ' and silly radius)
The lack of constant autoheal (fairy) seems to be addressed with crossing sect. Perhaps a longer hot to imitate the fairy better?

Beside CI being really weak, what else is missing from Noct AST actually?