So the devs probably made the class World Enemy with Instant Death Immunity and TGOALID immunity. This way whenever they have a world enemy they can just give it the class and forget about it.   Isn't the logical explanation that they are immune to world items, like true Dragons, so they have immunity to TGOALID because its effect is similar to Longinus

It isn't. TGOALID acts more like a meta magic that effects the users Instant Death Spells/Skills. Without an Instant Death Spell / Skill it is pointless on its own.  

It doesn't matter what happens before he pulls the trigger, I'm talking about the outcome.

It doesn't matter what happens before it pulls the trigger, I'm talking about the outcome.

hey were killed by dragons breath and were resurrected.

Dragon Lords don't have traditional breath attacks like normal Dragons, but instead use Wild Magic. The effects could be as simple as reproducing fire to ripping your soul from your body.

Yes I know, I meant wild magic spells in the form of breathing spells

Also there is no evidence that resurrection is impossible, Except for soulbreaker ، Even Platinum Dragon's final attack couldn't kill Shalltear with a single blow in the web novel.

I think in the side story Ainz didn't have the resurrection wands, which were left behind by his friends because they are in the treasury.

because they don't have world protection

World Protection only protects you from World Items. TGOALID is a skill, so it wouldn't specifically protected you against it... although if that was the effect of the World Item, then maybe

As I said in my theory, TGOALID is the inferior version of Longinus, so its influence is considered as a world item.

Ainz used Cry of the Banshee which is an AOE instant death spell. It starts where the user is and moves out

I knew some of you would say this, so I didn't say how Ainz survived against Cure Elim, because the super spell works as you explained, the Imperial soldiers who were behind Ainz didn't get killed .

but that's wrong.

Then, Ainz’s trump card took effect.

In that moment — the world died.

This was not metaphorical.

Everything died.

The Einherjar evaporated into white mist as it couched its lance, and dispersed before Ainz’s eyes. Even a homunculus with no concept of life died instantly. Shalltear’s familiars shared the same fate, unable to resist the destruction which overtook them.