What's up with AST's Noct shield delay?!

[Pharazon]

Depending on latency and the cast time of the ability you will see this happen with shields. Spells lock it at around 85%, proven by the fact you can start moving around that time and still have your cast finish. This is likely true with the "state of the game" used for calculations and the order in which calculations are handled. I believe the shield creation itself is lower priority than heals and damage and is not retroactively applied. To better illustrate what I mean:

Spell Lock-In (Damage and Healing now have highest priority)
Heal Lands (triggers shield creation but has lower priority than damage)
Damage is applied
Shield is created.

Because of latency for you and your party and the fact that I don't believe the people furthest away in an AOE situation are receiving the healing/shield at the same time as those closer to you, you will notice some heals land before the lock-in giving you the shield and some land just after so you get the heal but the shield doesn't get used.

[Leaping]

Spell Lock-In (Damage and Healing now have highest priority)
Heal Lands (triggers shield creation but has lower priority than damage)
Damage is applied
Shield is created.

Interesting thing to know!

[CyrilLucifer]

Yeah, it's a bit annoying, but you get used to it after a while. I find it most irritating during adds, honestly.

With a bit of practice (read: slightly early casting) you can Shield both the tankbuster and the cleave after.